MEMCAL    SCHOOL 


Gift  of 
Mrs.  E.M.  Lartigau 


MANUAL  OF  SURGICAL  ANATOMY 


A  MANUAL 


OF 


SURGICAL  ANATOMY 


BY 


LEWIS  BEESLY,  F.R.C.S.,  EDIN. 

ASSISTANT  SURGEON,  CHALMERS*  HOSPITAL,  EDINBURGH  5  LECTURER  ON 
SURGERY  AND  OPERATIVE  SURGERY,  EDINBURGH  SCHOOL  OF  MEDICINE  FOR 
WOMEN  J  LECTURER  ON  SURGICAL  APPLIED  ANATOMY,  EDINBURGH  POST- 
GRADUATE COURSES  5  EXAMINER  IN  ANATOMY,  ROYAL  COLLEGE  OF  SURGEONS, 
EDINBURGH;  LATELY  DEMONSTRATOR  OF  ANATOMY,  EDINBURGH  UNIVERSITY 


AND 


T.  B.  JOHNSTON,  M.B.,  Ch.B. 

LECTURER    AND  DEMONSTRATOR  OF  ANATOMY,  UNIVERSITY    COLLEGE,  LONDON  ; 

LATELY  LECTURER  AND  DEMONSTRATOR  OF  ANATOMY,  EDINBURGH  UNIVERSITY, 

AND    LECTURER   ON    MEDICAL   APPLIED  ANATOMY,   EDINBURGH    POST-GRADUATE 

COURSES 


NEW  YORK 

WILLIAM    WOOD    AND    COMPANY 
1916 


Printed  in  Great  Britain  by  R.  S:  R.  CLARK,  LIMITED,  Edinburgh. 


PREFACE. 


THE  production  of  a  new  book  on  Surgical  Anatomy  calls  for 
a  word  of  explanation.  For  some  years  past,  while  acting  as 
Demonstrators  of  Anatomy  in  the  University  of  Edinburgh,  we 
have  been  struck  by  the  fact  that  senior  students  and  graduates, 
when  working  in  the  dissecting  room,  seldom  make  use  of  any 
of  the  numerous  excellent  works  on  Surgical  Anatomy.  They 
seem  to  prefer  standard  books  on  Regional  Anatomy ;  and 
while  they  assimilate  the  anatomical  facts,  they  frequently 
fail  to  appreciate  their  surgical  application.  Recognising  that, 
when  possible,  Surgical  Anatomy  should  be  studied  from  dis- 
sections, we  have  endeavoured  to  present  the  subject  in  a  form 
suitable  for  use  in  the  dissecting  room.  The  general  framework 
of  this  book  is  founded  on  a  series  of  lectures  on  Surgical  Anatomy 
delivered  by  one  of  the  authors  in  connection  with  the  Edinburgh 
Post-Graduate  Course. 

While  it  has  been  found  impossible  to  avoid  encroaching 
on  the  subject  of  Operative  Surgery,  an  endeavour  has  been 
made  to  bring  into  prominence  the  anatomy  of  the  operations, 
excluding  as  far  as  possible  the  details  of  surgical  technique. 
In  order  to  keep  the  size  of  the  volume  within  bounds,  it  has 
been  found  necessary  to  omit,  almost  entirely,  the  descriptions 
of  amputations  of  the  limbs. 

On  account  of  the  frequency  with  which  tuberculous  disease 
of  bones  and  joints  starts  in,  and  spreads  from,  the  ends  of  the 
diaphyses  (metaphyses),  special  attention  has  been  given  to 
the  anatomical  relations  which  these  regions  and  the  adjacent 
epiphyses  bear  to  the  capsules  and  synovial  reflections  of  the 
corresponding  joints  ;  and  in  order  to  emphasise  the  importance 
of  these  relations,  we  have  included  a  number  of  figures  in  which 
they  are  illustrated. 

R2333 


The  published  works  of  numerous  authors  have  been  con- 
sulted from  time  to  time,  and  we  would  specially  acknowledge 
our  indebtedness  to  the  writings  of  Mackenzie  and  Sherren,  to 
whom  reference  is  frequently  made  in  the  different  sections. 

To  Mr.  Harold  Stiles,  whose  teaching  has  formed  the  in- 
spiration of  this  book,  we  desire  to  express  our  sincere  thanks 
for  the  valuable  advice  and  suggestions  with  which  he  has  so 
frequently  helped  us.  As  one  of  the  authors  has  had  the 
privilege  of  being  associated  with  Mr.  Stiles  for  some  years,  our 
debt  to  him  is  even  greater  than  is  indicated  by  the  frequent 
recurrence  of  his  name  in  the  text. 

We  also  desire  to  offer  our  warmest  thanks  to  Professor 
Robinson,  who,  in  addition  to  having  placed  much  of  his  material 
at  our  disposal  for  the  purposes  of  illustration,  has  frequently 
given  us  the  benefit  of  his  criticism  and  advice.  We  are  also 
indebted  to  Dr.  E.  B.  Jamieson,  whose  counsel  on  the  subject 
of  nomenclature  and  on  points  of  anatomical  detail  was  often 
sought ;  and  to  Mr.  R.  J.  M.  Home,  who  gave  us  much  help 
while  the  volume  was  passing  through  the  press. 

The  radiograms,  except  when  otherwise  acknowledged, 
are  the  work  of  Dr.  Edmund  Price,  whose  kindness  we  highly 
appreciate.  We  also  desire  to  thank  our  publishers  for  allowing 
us  to  reproduce  many  of  the  excellent  illustrations  in  Cunning- 
ham's Textbook  of  Anatomy  and  in  Cunningham's  Manual  of 
Practical  Anatomy.  The  numerous  new  illustrations  and 
diagrams  have  been  drawn  for  us  by  Mr.  J.  T.  Murray,  to  whom 
we  are  greatly  indebted  for  the  skill  and  care  which  he  has 
expended  upon  them. 

L.  B. 
T.  B.  J. 

EDINBURGH,  1915.' 


CONTENTS. 


SECTION  I.— THE  SUPERIOR  EXTREMITY. 

PAGE 

THE  SHOULDER  REGION      ...  i 

THE  BREAST  AND  AXILLA              .                                     .  24 

THE  REGION  OF  THE  (UPPER)  ARM         ...  38 
THE  REGION  OF  THE  ELBOW        .            .                        .44 

THE  FOREARM  AND  WRIST            .            .  65 

THE  HAND     .......  80 

THE  BRACHIAL  PLEXUS  AND  ITS  BRANCHES      .            .  95 


SECTION  II.— THE  HEAD  AND  NECK. 

THE  NECK      .  .  .  .  .  .  .        107 

THE  FACE,  MOUTH,  AND  PHARYNX         .  .  .170 

THE  NOSE  AND  AIR  SINUSES        ....        194 

THE  EYE       .....  .203 

THE  AUDITORY  APPARATUS  ....       209 

THE  HEAD     .  .  .  .  .  .  .        218 

THE  BRAIN  AND  ITS  MENINGES    .  .  .       223 


SECTION  III.— THE  ABDOMEN  AND  PELVIS. 

THE  ABDOMINAL  WALLS     .  .  .  .  .237 

THE  ABDOMINAL  CAVITY    .....       276 

THE  PELVIS  .......       355 

vii 


PAGE 


THE  PERINEUM         ......       373 

THE  FEMALE  PELVIS  .....       387 

SECTION  IV.— THE  INFERIOR  EXTREMITY. 

THE  FRONT  OF  THE  THIGH  ....       398 

THE  GLUTEAL  REGION        .  .  .  .  .413 

THE  HIP  JOINT        ....  .       419 

THE  REGION  OF  THE  KNEE  .  .  .  .441 

THE  LEG        .......       468 

THE  REGION  OF  THE  ANKLE  AND  FOOT  .  .       477 

THE  NERVES  OF  THE  LOWER  LIMB         .  .  .       499 

SECTION  V.— THE  THORAX  AND  VERTEBRAL 
COLUMN. 

THE  THORACIC  WALL  .....  502 
THE  THORACIC  CONTENTS  .....  505 
THE  POSTERIOR  THORACIC  WALL  .  .  .513 

THE  VERTEBRAL  COLUMN  .  .  .  .  .516 

THE  SPINAL  MEDULLA        .  .  .  .  .524 

INDEX          .  .  .  .  .  -539 


LIST  OF   ILLUSTRATIONS. 


FIG.  PAGE 

1.  Surface  landmarks  of  the  shoulder  region  .  .  3 

2.  The  nerve-supply  of  the  skin  on  the  ventral  aspect 

of  the  trunk  .....  5 

3.  The  nerve-supply  of  the  skin  on  the  dorsal  aspect 

of  the  trunk              .....  7 

4.  The  sterno-clavicular  joints  ....  8 

5.  Shoulder  of  child,  aged  six.      (Radiogram)              .  16 

6.  Frontal  section  through  the  right  shoulder-joint  .  17 

7.  Sub-coracoid  dislocation  of  shoulder- j  oint.     (Radio- 

gram) ......          21 

8.  The  connections  of  the  pectoral  lymphatic  plexus         27 

9.  Diagram  of  a  section  through  the  anterior  wall  of 

the  axilla       ......  30 

10.  The  axilla  and  its  lymph  glands       ...  36 

11.  The  back  of  the  arm  .....  40 

12.  The  superficial  nerves  and  veins  on  the  front  of  the 

upper  limb    ...  .  .  .  .46 

13.  The  superficial  nerves  on  the  dorsal  aspect  of  the 

upper  limb    ......          47 

14.  Schematic  representation  of  the  distribution  of  the 

spinal  nerves  to  the  skin  on  the  anterior  aspect 

of  the  upper  limb    .....          48 

15.  Schematic  representation  of  the  distribution  of  the 

spinal  nerves  to  the  skin  on  the  dorsal  aspect  of 

the  upper  limb         .....          49 

1 6.  Normal  elbow  of  an  adult  female.     (Radiogram) .          52 

17.  Frontal  section  through  the  elbow  and  proximal 

radio-ulnar  joints     .  .  .  .  -53 

1 8.  Sagittal  section  through  the  elbow- joint     .  .          54 

19.  Elbow  of  child,  aged  four.     (Radiogram)   .  .          55 

20.  Elbow-joint  of  boy,  aged  fourteen.     (Radiogram)          56 

21.  Elbow-joint  of  child,  aged  five.      (Radiogram)       .          57 

ix 


C  .Lib!    U.P 

FIG.  PAGE 

22.  Elbow-joint  of  child,  aged  five.     (Radiogram)      .         59 

23.  Elbow-joint  of  adult,  showing  fracture  of  olecranon 

(Radiogram)  .....         64 

24.  Surface  landmarks  on  the  dorsal  aspect  of  the 

superior  extremity  .  .  .  .  .67 

25.  The  anterior  aspect  of  the  forearm  .  .          70 

26.  The  muscles  on  the  dorsal  aspect  of  the  forearm  .          74 

27.  Section  through  the  carpus,  to  show  the  various 

joint  cavities  .....          76 

28.  Carpus  of  an  adolescent,  aged  sixteen.     (Radio- 

gram) ......          78 

29.  Longitudinal  section  through  the  third  finger        .          83 

30.  The  positions  of  the  vessels  and  nerves  relative  to 

the  bones  of  the  hand  and  wrist  .  .          85 

31.  Diagram    of    a    transverse    section    through    the 

carpus,  to  show  the  arrangement  of  the  synovial 
sheaths          .  .....          87 

32.  The  synovial  sheaths  of  the  wrist  and  hand          .          89 

33.  The  hand  of  a  child,  aged  three,  showing  tuber- 

culous dactylitis.      (Radiogram)    ...          94 

34.  Diagram  of  the  brachial  plexus        ...         96 

35.  Superficial  nerves  and  veins  of  the  neck     .  .109 

36.  Transverse  section  through  neck,  at  level  of  seventh 

cervical  vertebra      .  .  .  .  .112 

37.  Transverse  section  through  neck,  at  level  of  third 

cervical  vertebra      .  .  .  .  .113 

38.  The  veins  and  lymph  glands  of  the  neck    .  .        118 

39.  The  side  of  the  neck  .  .  .  .  .123 

40.  Diagram  of  the  sympathetic  trunk  in  the  neck  .        124 

41.  Bilateral  cervical  ribs.      (Radiogram)  .  .128 

42.  The  veins  and  lymph  glands  of  the  neck    .  .        133 

43.  Exposure  of  the  posterior  rami  of  the  upper  cervical 

nerves  ......        137 

44.  The  deep  triangle  of  the  neck  .  .  .140 

45.  Frontal  section  through  the  mouth  .  .146 

46.  Scheme  showing  the  branchial  pouches,  clefts  and 

arches  and  some  of  their  derivatives       .  .        150 

47.  Surgical  approach  for  the  removal  of  advanced 

malignant  disease  of  the  tongue  .  .  .        153 

48.  Upper  aperture  of  the  larynx  .  .  .156 

49.  The  larynx  as  seen  in  the  living  subject  by  means 

of  the  laryngoscope              .            .  .  .158 

50.  Median  section  through  head  and  neck  .  .160 

51.  The  anterior  median  line  of  the  neck  .  .165 

52.  The  nerves  of  the  face            .            .  .  .173 


ur 

FIG.  PAGE 

53.  Section  through  the  mandibular  joint  .  .179 

54.  Varieties  of  alveolar  abscess              .  .  .185 

55.  The  development  of  the  face             .  .  .        191 

56.  Frontal   section    through   the   face    of  a   human 

embryo  at  the  seventh  week         .  .  .192 

57.  Radiogram  of  skull,  showing  normal  maxillary  and 

frontal  sinuses          .  .  .  .  .196 

58.  Empyaema  of  maxillary  sinus.     (Radiogram)         .        197 

59.  Empyaema  of  left  frontal  sinus.      (Radiogram)       .        201 

60.  Lateral  radiogram  of  skull     .  .  .  .202 

61.  Diagram  of  a  sagittal  section  through  the  eye      .        203 

62.  Diagram  of  the  naso-lacrimal  duct  and  its  con- 

nections        ......        205 

63.  Frontal  section  through  the  orbit     .  .  .        207 

64.  Left   tympanic   membrane    (as   viewed   from   the 

external  acoustic  meatus)  .  .  .  .212 

65.  Section  of  a  left  temporal  bone  along  the  line  of  the 

tegmen  tympani       .  .  .  .  .213 

66.  Dissection    of    the    tympanic    antrum    from    the 

lateral  side    .  .  .  .  .  .217 

67.  Frontal     section     through    the    scalp,     cranium, 

meninges,  and  cortex  cerebri         .  .  .        220 

68.  Oblique  section  through  the  posterior  part  of  the 

skull,  showing  the  relationship  of  the  dura  mater 

to  the  cerebral  sinuses        .  .  .  .224 

69.  Median  section  through  the  brain    .  .  .        226 

70.  Cranio-cerebral  topography    .  .  .  .228 

71.  Surface  landmarks  of  the  anterior  abdominal  wall       238 

72.  The  nerve-supply  of  the  skin  on  the  ventral  aspect 

of  the  trunk  .....        241 

73.  Diagram    to    illustrate    the    viscero  -  sensory  and 

viscero-motor  reflexes         ....        243 

74.  The  muscles  on  the  dorsal  aspect  of  the  trunk     .        245 

75.  Diagram  to  illustrate  the  method  of  closing  wounds 

in  the  supra-umbilical  part  of  the  linea  alba     .       247 

76.  The  lines  of  some  of  the  common  incisions  in  the 

abdominal  wall         .....        249 

77.  Sections  in  the  long  axis  of  the  inguinal  canal      .        256 

78.  Diagrams  to  illustrate  the  different  conditions  of 

the  processus  vaginalis       ....       258 

79.  Diagram  of  interparietal  interstitial  inguinal  hernia       260 

80.  Diagram     of    extraparietal    interstitial    inguinal 

hernia  ......       261 

81.  Diagram    of    a    transverse    section    through    the 

scrotum  and  testes  266 


FIG. 


82.  Transverse  section  through  the  abdomen,  showing 

the  spread  of  a  perinephric  abscess          .  .270 

83.  Transverse  section  through  the  abdomen  below  the 

kidneys  ......        272 

84.  The  position  and  posterior  relations  of  the  kidney       274 

85.  Sagittal  section  of  abdomen,  showing  the  arrange- 

ment of  the  peritoneum     .  .  .  .278 

86.  Transverse  section  of  abdomen,  at  the  level  of  the 

epiploic  foramen  (of  Winslow)       .  .  .280 

87.  Transverse  section  of  abdomen,  immediately  below 

the  epiploic  foramen  .  .  .  .281 

88.  The  posterior  wall  of  the  infra-colic  compartment       284 

89.  Schema  of  sagittal  section  of  embryo  after  the 

formation  of  the  head  and  tail  folds       .  .       287 

90.  Schema  of  a  sagittal  section  through  a  human 

embryo,  after  the  rotation  of  the  intestinal  loop       288 

91.  Normal  hypertonic  stomach.     (Radiogram)  .        291 

92.  High  position  of  the  pylorus.     (Radiogram)          .       292 

93.  Radiogram  of  stomach,  showing  typical  J  outline       293 

94.  Stomach  of  a  child.     (Radiogram)   .  .  .       295 

95.  The  arteries  and  lymph  glands  of  the  stomach     .        297 

96.  Exposure  of  the  terminal  part  of  the  bile-duct       .       305 

97.  Surface  relations  of  the  liver  and  stomach  .       308 

98.  Diagrams  to  show  the  varying  modes  of  termina- 

tion of  the  bile-duct  and  the  pancreatic  duct     .       316 

99.  Dissection  to  expose  the  spleen        .  .  .320 

100.  A  coil  from  the  upper  part  of  the  jejunum  .       323 

101.  A  coil  from  the  lower  part  of  the  ileum     .  .       324 

102.  Partial  prolapse  of  the  caecum.     (Radiogram)       .        326 

103.  Persistence  of  the  vitello-intestinal  duct     .  .       328 

104.  Diagrams    illustrating    the    different    peritoneal 

relationships    of    the    caecum    and    vermiform 
process  ......       332 

105.  "  Double-barrelled  "  colon.     (Radiogram)  .  .       335 

1 06.  The  arteries  and  lymph  glands  of  the  large  in- 

testine ......       337 

107.  The  posterior  wall  of  the  infra-colic  compartment       342 

1 08.  Small  calculus  impacted  in  right  ureter.     (Radio- 

gram) .  -347 

109.  Calcareous  mesenteric  lymph  gland.     (Radiogram)        348 
no.  Calculus  in  the  renal  pelvis.     (Radiogram)  .       352 
in.  Basal  aspect  of  the  bladder  ....       358 

112.  Vesical  calculus.     (Radiogram)         .  .  .       360 

113.  Radiogram  showing  the  lower  abdominal  and  the 

pelvic  portions  of  the  ureters        .  .  .363 


114.  Diagram  of  the  pelvic  fascia  .  .  .374 

115.  Median  section  through  the  male  pelvis      .  -375 

1 1 6.  The  segmental  supply  of  the  skin  in  the  perineum       377 

117.  Median  section  through  the  female  pelvis  .  .        388 

1 1 8.  The  superficial  nerves  and  veins  on  the  anterior 

aspect  of  the  lower  limb    ....        399 

119.  The  subinguinal  lymph  glands  and  the  fossa  ovalis       401 

120.  Sagittal  section  through  the  femoral  canal  .        403 

121.  The  femoral  trigone     .....        407 

122.  Transverse  section  through  the  thigh          .  .        412 

123.  The  gluteal  region       .  .  .  .  .417 

124.  The  cutaneous  nerves  on  the  posterior  aspect  of  the 

lower  limb     ......       419 

125.  Oblique  section  through  the  right  hip-joint  .       422 

126.  Congenital  dislocation  of  the  hip-joint.     (Radio- 

gram) ....       429 

127.  Surface  landmarks  in  the  region  of  the  knee  .   442 

128.  The  medial  side  of  the  knee  .  .  .        444 

129.  Normal  knee-joint  of  a  child,  aged  four.     Antero- 

posterior  view.     (Radiogram)        .  .  .450 

130.  Knee-joint  of  child,  aged  thirteen.     Lateral  view. 

(Radiogram)  .  .  .  .  .451 

131.  Sagittal  section  through  the  knee-joint       .  -453 

132.  Oblique  section  through  the  right  knee-joint         .        454 

133.  The  menisci  and  their  attachments  .  .        456 

134.  Diagrams    to    illustrate    injuries    of    the    medial 

meniscus        .  .  .  .  .  -457 

135.  Complete  exposure  of  the  knee-joint  .  .        461 

136.  Genu  valgum.     (Radiogram)  .  .  .        464 

137.  Diagram  to  illustrate  how  a  fractured  patella  may 

be  wired,  without  interfering  with  the  articular 
surface  ......        467 

138.  The  front  of  the  leg  and  dorsum  of  foot     .  .       470 

139.  The  lateral  aspect  of  the  ankle  and  foot     .  .        473 

140.  The  bony  landmarks  on  the  lateral  aspect  of  the 

ankle  and  foot          .  .  .  .  .478 

141.  The  surface  landmarks  on  the  medial  side  of  the 

ankle  and  foot          .  .  .  .  .479 

142.  Normal   ankle-joint   of   a   child,    aged    fourteen. 

(Radiogram)  .....       480 

143.  Frontal  section  through  the  ankle-joint      .  .       482 

144.  Sagittal   section    of   foot,    showing   some    of   the 

articulations  .....       483 

145.  Normal  ankle-joint.     Lateral  view.     (Radiogram)       489 

146.  Avulsion  fracture  of  the  calcaneus.     (Radiogram)      490 


FIG.  PAGE 

147.  Transverse  section  through  the  foot  .  493 

148.  Diagram  of  the  sacral  plexus  .  .  .  500 

149.  Diagram  of  a  transverse  section  through  the  thorax  506 

150.  Surface  relations  of  the  lungs,  heart,  and  pleural 

sacs     .......       507 

151.  Surface  relations  of  the  right  lung  and  pleural  sac. 

Lateral  view  .  .  .  .  .508 

152.  Transverse    section    through    the    thorax,    fourth 

thoracic  vertebra     .  .  .  .  .512 

153.  Transverse     section     through     a     typical     costo- 

vertebral  joint          .  .  .    •         .  .513 

154.  Transverse  section  through  the  upper  part  of  the 

posterior  mediastinum        .  .  .  .514 

155.  Transverse  section  through  the  superior  media- 

stinum .  .  .  .  .  .515 

156.  Ossification  of  a  vertebra       .  .  .  .516 

157.  Kyphosis,    produced    by    tuberculous    disease    of 

thoracic  vertebrae.     (Radiogram)  .  .       517 

158.  Pott's  disease  in  thoracic  region  of  a  child.    (Radio- 

gram) ......  518 

159.  Scheme  of  the  distribution  of  a  typical  spinal  nerve  521 

1 60.  The  spinal  medulla  in  situ     .  .  .  525 

161.  Diagram  of  a  transverse  section  through  the  spinal 

medulla         ......       526 

162.  Unilateral    rotatory    dislocation    of    the    fourth 

cervical  vertebra      .  .  .  .  .528 

163.  Diagrammatic  representation  of  the  chief  motor 

and  sensory  tracts  in  the  central  nervous  system       531 

164.  Diagram    illustrating    some     of    the    congenital 

anomalies  of  the  vertebral  column  and  spinal 
medulla         .  535 


MANUAL 


OF 


SURGICAL    ANATOMY. 


THE  SUPERIOR  EXTREMITY. 

THE  SHOULDER  REGION. 

Surface  Landmarks. — The  Clavicle  is  the  most  important 
surgical  landmark  in  this  region.  Its  axis  is  directed  downwards,, 
forwards.,  and  medially  in  well  -  developed  subjects,  but  in 
poorly  -  developed  individuals  the  bone  assumes  a  horizontal 
position.  The  skin,  superficial  fascia,  and  platysma  are  all 
freely  movable  over  its  subcutaneous  surface,  and  therefore 
compound  fracture  is  a  rare  injury. 

The  large  sternal  end  of  the  clavicle  forms  a  rounded 
prominence  immediately  to  the  lateral  side  of  the  jugular 
(supra-sternal)  notch  and  the  sternal  head  of  the  sterno-mastoid. 
In  its  medial  two-thirds  the  shaft  is  convex  forwards  and 
laterally,  and  this  convexity  is  often  greatly  exaggerated  in 
children  with  rickets.  The  lateral  third  is  concave  forwards, 
and  on  its  anterior  border  there  is  a  tubercle,  of  varying  size, 
which  is  produced  by  the  deltoid.  The  middle  third  forms 
the  upper  boundary  of  the  superficial  infra-clavicular  triangle, 
which  is  not  always  a  well-marked  depression.  Its  distinctness 
depends  on  the  proximity  and  development  of  the  other  borders, 
namely,  the  anterior  margin  of  the  deltoid  and  the  upper  margin 
of  the  clavicular  head  of  the  pectoralis  major.  On  deep  pressure 
in  this  triangle  just  below  the  clavicle,  the  pulsations  of  the 
first  part  of  the  axillary  artery  may  be  felt,  and  the  vessel  can 

1 


2  THE  SUPERIOR  EXTREMITY 

be  compressed  downwards,  backwards,  and  medially  against 
the  second  rib. 

The  lateral  border  of  the  acromial  end  of  the  clavicle  is 
marked  by  a  weak  ridge  directed  from  before  backwards,  i£ 
inches  medial  to  the  lateral  border  of  the  acromion.  When 
the  acromio-clavicular  ligaments  are  lax,  it  is  possible  to  insinuate 
the  finger-nail  between  the  articular  surfaces  of  the  joint.  An 
adventitious  subcutaneous  bursa  is  occasionally  met  with  over 
this  region  in  those  accustomed  to  carrying  heavy  weights 
upon  the  shoulder. 

The  coracoid  process  of  the  scapula  is  not  situated  in  the 
superficial  infra-clavicular  triangle,  but  lies  under  cover  of  the 
anterior  border  of  the  deltoid.  It  can  be  felt  on  direct  backward 
pressure  one  inch  below  the  clavicle  lateral  to  the  junction  of 
its  middle  and  lateral  thirds. 

The  apex  of  the  acromion  is  placed  one  quarter  to  half  an  inch 
in  front  of  the  acromio-clavicular  joint.  Its  lateral  border 
can  be  traced  backwards  for  about  two  inches,  till  it  joins  the 
inferior  border  of  the  scapular  spine,  which  meets  it  at  the 
sharp  acromial  angle.  When  the  upper  arm  is  measured  in 
suspected  fracture  of  the  humerus,  the  acromial  angle  is  utilised 
instead  of  the  acromion  apex,  the  latter  being  more  obscured 
by  the  deltoid.  The  subcutaneous  upper  surface  of  the  acromion 
can  be  readily  examined  when  the  arm  is  supported  in  the 
abducted  position,  although  the  medial  border  is  overlapped 
by  the  trapezius  and  the  lateral  by  the  deltoid. 

The  spine  of  the  scapula  can  be  traced  medially  and  downwards 
to  its  flattened  root  opposite  the  third  thoracic  spine. 

The  superior  border  and  the  medial  (superior)  angle  of  the 
scapula  are  on  a  level  with  the  second  rib,  but  cannot  be  palpated 
easily,  since  they  are  under  cover  of  the  trapezius  and  the 
supra-spinatus.  They  can  be  examined  if  the  upper  fibres  of 
the  trapezius  are  relaxed  by  carrying  the  patient's  arm  as  far 
as  possible  over  the  opposite  shoulder. 

The  lower  three-fourths  of  the  vertebral  border,  the  inferior 
angle,  which  lies  over  the  seventh  rib  or  seventh  intercostal 
space,  and  the  lower  part  of  the  axillary  border,  can  all  be 
palpated,  if  the  patient's  forearm  is  carried  behind  his  back  so  as 
to  relax  the  trapezius,  the  rhomboids,  and  the  latissimus  dorsi. 

The  anterior  fold  of  the  axilla  is  formed  by  the  lower  border 
of  the  pectoralis  major,  which,  at  its  medial  attachment,  follows 
the  line  of  the  fifth  rib.  A  line,  drawn  from  the  lower  margin 


THE  SHOULDER  REGION 


of  the  sternal  end  of  the.  clavicle  to  the  lower  limit  of  the  insertion 
of  this  muscle,  outlines  the  lower  border  of  its  clavicular  head 
and  indicates  the  plane  of  separation  usually  adopted  in  removal 
of  the  muscle  in  complete  excision  of  the  breast  (Stiles). 


Coracoid  process 
Acromio-clavicular  joint 


Acromion 


Greater  tubercle 


FIG.    i. — Surface  Landmarks  of  the  Shoulder  Region. 

The  Deltoid,  with  its  wide  V-shaped  origin  from  the  anterior 
border  of  the  lateral  part  of  the  clavicle,  the  lateral  border  of 
the  acromion,  and  the  lower  border  of  the  scapular  spine  and 
its  pointed  insertion  half-way  down  the  lateral  side  of  the 
humerus,  is  a  conspicuous  landmark.  It  overlies  the  greater 
tubercle  (tuberosity),  which  is  the  most  lateral  bony  point  in 
the  body,  and  so  gives  the  shoulder  its  smooth  convex  contour. 

Direct  injuries  around  the  greater  tubercle  of  the  humerus 


4  THE  SUPERIOR  EXTREMITY 

are  often  very  difficult  to  diagnose,  owing  to  the  depth  of  the 
bone  from  the  surface  and  to  the  bruising  and  effusion  which 
supervene.  An  increase  in  the  antero-posterior  diameter  of 
the  greater  tubercle  can  be  determined  by  grasping  that  land- 
mark between  the  fingers  and  thumb  and  comparing  it  with 
the  greater  tubercle  of  the  opposite  side.  It  is  very  suggestive 
of  fracture  in  this  part  of  the  bone,  but  accurate  diagnosis  is 
possible  only  by  means  of  the  X-rays. 

The  lesser  tubercle  (small  tuberosity)  of  the  humerus  points 
directly  forwards  and  lies  one  inch  lateral  to  the  coracoid  process 
and  on  a  slightly  lower  plane.  It  also  lies  under  cover  of  the 
deltoid.  On  deep  pressure  over  them,  the  tubercles  can  be 
felt  to  slip  from  under  the  finger,  if  the  humerus  is  rotated 
alternately  medially  and  laterally.  Immediately  to  the  lateral 
side  of  the  lesser  tubercle  lies  the  intertubercular  sulcus  (bicipital 
groove)  containing  the  long  tendon  of  the  biceps.  This  groove 
corresponds  to  the  lower  two-thirds  of  a  line  three  inches  long, 
drawn  from  the  tip  of  the  acromion  down  the  arm  in  the  axis 
of  the  humerus. 

When  the  arm  is  by  the  side,  the  inferior  margin  of  the 
head  of  the  humerus  is  easily  palpated  through  the  floor  of  the 
axilla.  As  the  arm  is  abducted,  more  of  the  head  becomes 
exposed  to  the  examining  finger,  but  it  is  less  distinctly  felt 
owing  to  the  tightening  of  the  axillary  fascia. 

Superficial  Nerves. — The  skin  of  the  shoulder  region  is 
supplied  in  front  by  the  descending  branches  of  the  cervical  plexus 
(C.  3  and  4). 

The  anterior  and  middle  supra-clavicular  branches  (supra- 
sternal  and  supra-clavicular)  extend  down  on  to  the  chest  wall 
as  far  as  the  second  intercostal  space,  where  they  are  overlapped 
by  branches  from  the  second  intercostal  nerve.  This  fact 
explains  the  constant  level  of  the  anterior  line  of  anesthesia  in 
fracture  dislocations  occurring  between  the  fifth  cervical  and 
second  thoracic  vertebrae,  and  also  the  referred  pain  sometimes 
felt  over  the  clavicle  in  Pott's  disease  of  the  third,  fourth,  and 
fifth  cervical  vertebrae.  Occasionally  the  supra-clavicular  nerves 
are  involved  in  callus  following  fracture  of  the  clavicle  and  cause 
persistent  neuralgia,  which  may  radiate  over  the  same  side  of 
the  head  and  neck.  The  posterior  supra-clavicular  (supra- 
acromial)  branches  extend  down  for  a  short  distance  over  the 
deltoid,  overlapping  the  cutaneous  branches  of  the  axillary 
(circumflex)  nerve  (Fig.  2). 


FIG.  2. — The  Nerve  Supply  of  the  Skin  on  the  Ventral  Aspect  of  the  Trunk. 
The  whole  of  the  area  shown  in  the  diagram  is  supplied  by  branches 
from  the  anterior  rami  (primary  divisions)  of  the  spinal  nerves. 

G.A,  Great  auricular  nerve;  S.C,  N.  cutaneus  colli ;  S.CL,  Supra-clavicular  nerves; 
ACK,  Posterior ;  ST,  Middle  ;  CL,  anterior ;  T.2-I2,  Lateral  and  anterior  branches 
of  thoracic  nerves;  I.H,  Ilio-hypogastric  nerve;  I.I,  IHo-inguinal  nerve;  CIRC, 
Cutaneous  branch  of  axillary  nerve  ;  L.I.C,  Medial  cutaneous  nerve  of  the  arm  (O.T. 
lesser  internal  cutaneous  nerve);  I.H,  Intercosto-brachial ;  I.C,  Medial  cutaneous 
nerve  of  the  forearm  (O.T.  internal  cutaneous);  M.S,  Cutaneous  branch  of  radial 
nerve  ;  E.C,  Lateral  cutaneous  nerves  ;  G.C,  Lumbo-inguinal  nerve  ;  M.C1  2,  Inter- 
mediate cutaneous  nerves  ;  I.C1,  Branch  of  medial  cutaneous  nerve  ;  P,  Branches  of 
pudendal  nerve  ;  S.Sc,  Branches  of  posterior  cutaneous  nerve  of  the  thigh. 

On  the  other  side  a  schematic  representation  is  given  of  the  areas  supplied  by  the  above 
nerves,  the  numerals  indicating  the  spinal  origin  of  the  branches  of  distribution  to 
each  area. 


6  THE  SUPERIOR  EXTREMITY 

Referred  pain  occurs  in  the  shoulder  region  in  diaphragm- 
atic pleurisy  and,  on  the  right  side,  in  tropical  abscess  of 
the  liver  and,  more  rarely,  in  pathological  conditions  of  the 
gall-bladder.  The  stimuli  reach  the  fourth  cervical  segment 
via  the  phrenic  nerve  (p.  242). 

Anteriorly,  as  already  mentioned,  the  skin  is  supplied  entirely 
by  C.  3  and  C.  4,  but  the  skin  of  the  corresponding  area  on  the 
dorsal  aspect  is  supplied  by  the  fourth  to  the  sixth  cervical  and 
the  upper  three  thoracic  nerves  (Fig.  3).  From  this  it  will 
be  seen  why,  in  fracture  dislocations  below  the  fourth  cervical 
vertebra,  the  line  of  anaesthesia  is  higher  on  the  posterior  than 
on  the  anterior  aspect  of  the  body. 

Below  the  shoulder,  i.e.  over  the  floor  of  the  axilla,  the  skin 
is  supplied  by  the  lateral  cutaneous  branches  of  the  second 
(intercosto-brachial,  p.  32)  and  third  intercostal  nerves. 

Superficial  Veins. — The  cephalic  vein  runs  upwards  in  the 
groove  between  the  deltoid  and  the  pectoralis  major,  and  passes 
backwards  through  the  superficial  infra-clavicular  triangle  to 
join  the  axillary  vein.  It  frequently  communicates  with  the 
external  jugular  by  means  of  a  small  vein  which  crosses  in 
front  of  the  clavicle  (Fig.  35).  This  vessel  becomes  considerably 
enlarged  in  those  cases  of  excision  of  the  breast  in  which  a 
portion  of  the  axillary  vein  has  been  excised,  as  it  offers  an 
efficient  channel  for  the  return  of  venous  blood  from  the 
upper  limb. 

Trapezius. — The  origin  of  this  muscle  extends  from  the 
occipital  bone  above  to  the  lowest  thoracic  spine.  The  upper 
fibres  are  attached  to  the  posterior  border  of  the  clavicle  in  its 
lateral  half.  They  support  the  clavicle,  and,  through  it,  part 
of  the  weight  of  the  upper  limb,  and  are  supplied  by  the  (spinal) 
accessory  nerve.  When  the  nerve  is  injured,  the  shoulder  on 
the  affected  side  falls  to  a  lower  level,  as  it  has  lost  its  muscular 
support.  The  lower  part  of  the  muscle  is  inserted  into  the 
medial  border  of  the  acromion  and  the  upper  border  of  the  spine 
of  the  scapula ;  and  it  is  supplied  by  the  cervical  plexus  (C.  3 
and  4).  A  bursa  is  situated  between  the  muscle  and  the  flattened 
root  of  the  scapular  spine.  When  the  whole  muscle  contracts, 
the  point  of  the  shoulder  is  elevated — particularly  by  the  upper 
fibres — and  it  is  owing  to  this  movement  that  abduction  of  the 
arm  is  possible  beyond  an  angle  of  90°. 

Sterno-Clavicular  Joint.— The  line  of  the  joint  passes 
from  above  downwards  and  laterally.  The  articular  surface  of 


FIG.   3. The  Nerve-Supply  of  the  Skin  on  the  Dorsal  Aspect  of  the  Trunk. 

The  dotted  line  indicates  the  limits  of  the  area  supplied  by  the  posterior 
ranii  (primary  divisions)  on  the  left  side  of  the  body. 


G.O.    Greater  occipital  nerve. 

ACK.    Posterior  supra-clavicular  nerves. 

CIRC.   Cutaneous   branches   of  axillary 


E.G.    Lateral     cutaneous     nerve     of 

thigh. 
S.Sc.    Posterior    cutaneous    nerve    of 

thigh. 


THE  SUPERIOR  EXTREMITY 


the  clavicle,  the  more  mobile  bone,  is  larger  than  the  sternal 
facet,  and,  below,  it  comes  into  contact  with  the  first  costal 
cartilage.  A  somewhat  loose  capsule,  lined  with  synovial 
membrane,  is  attached  to  the  margins  of  the  articular  surfaces. 
It  is  thickened  in  front  and  behind  by  the  anterior  and  posterior 
sterno-clavicular  ligaments.  Anteriorly,  the  sterno-clavicular 
joint  is  covered  by  the  sternal  head  of  the  sterno-mastoid,  and, 
posteriorly,  it  is  in  relation  to  the  sterno-hyoid  and  the  sterno- 
thyreoid  muscles. 


Joint  capsule 
Joint  cavity 


Interarticular 
ligament 


Joint  cavity 


Anterior  chondro- 
sternal  ligament 


FIG.   4. — Sterno-Clavicular  and  Costo-Sternal  Joints. 

The  joint  is  divided  into  a  medial  or  inferior  and  a  lateral 
or  superior  compartment  by  a  disc-shaped  meniscus,  which  is 
attached  to  the  clavicle  above,  the  first  costal  cartilage  below, 
and  to  the  capsule  in  front  and  behind.  When  the  arm  is 
hanging  by  the  side  the  upper  compartment  is  V-shaped,  but 
when  the  arm  is  raised  the  upper  part  of  the  disc  is  thrust 
medially  by  the  clavicle,  and  both  compartments  become  slit- 
like.  The  disc  acts  as  a  buffer  between  the  clavicle  and  the 
sternum  and  serves  to  diminish  the  results  of  indirect  violence. 

Two   accessory   ligaments   strengthen  the   joint :     (i)   The 


THE  SHOULDER  REGION  9 

inter-clavicular  ligament,  which  stretches  from  clavicle  to  clavicle 
across  the  upper  surface  of  the  capsule  and  dips  down  in  the 
centre  to  become  attached  to  the  jugular  (supra-sternal)  notch  ; 
(2)  The  costo-davicular  (rhomboid)  ligament,  which  connects  the 
under  surface  of  the  sternal  extremity  of  the  clavicle  to  the 
upper  surface  of  the  first  costal  cartilage. 

Movements. — The  sterno-clavicular  joint  acts  as  a  hinge 
for  the  clavicle,  so  that  when  the  acromial  end  of  the  bone  is 
elevated  or  depressed,  carried  forwards  or  backwards,  the 
sternal  end  passes  in  the  opposite  direction.  In  elevation  or 
depression  of  the  point  of  the  shoulder  the  sternal  end  of  the 
clavicle  moves  over  the  surface  of  the  articular  disc,  but  when 
the  shoulder  is  thrust  forwards  or  backwards  the  disc  moves 
with  the  clavicle  over  the  clavicular  facet  on  the  sternum. 
Excessive  upward  movement  of  the  shoulder  is  checked  by  the 
tension  of  the  costo  -  clavicular  ligament,  and  the  opposite 
movement  by  the  tension  of  the  articular  disc  and  the  inter- 
clavicular  ligament. 

The  anterior  supra-clavicular  (supra- sternal)  nerves  (C.  3  and  4) 
supply  the  joint,  and  branches  from  the  internal  mammary  and 
the  clavicular  branch  of  the  thoraco-acromial  (thoracic  axis)  artery 
anastomose  around  it. 

In  Dislocations  of  the  Joint  the  sternal  end  of  the  clavicle 
usually  passes  forwards,  tearing  the  anterior  sterno-clavicular 
ligament.  The  direction  taken  by  the  bone  is  said  to  be  due 
to  the  weakness  of  this  ligament,  but  it  is  more  probable  that  it 
depends  on  the  application  of  the  force  along  the  axis  of  the 
clavicle.  Though  this  dislocation  is  easy  to  reduce  by  pulling 
the  two  shoulders  backwards,  it  is  difficult  to  retain  the  bones 
in  apposition  owing  to  the  normal  obliquity  of  their  articular 
surfaces. 

Backward  dislocation  is  rare,  and  is  caused  either  by  indirect  force  thrusting 
the  shoulder  forwards,  or  by  direct  violence  from  in  front  at  the  sternal 
end  of  the  clavicle.  In  this  injury  the  posterior  sterno-clavicular  ligament 
is  torn,  and  the  clavicle  passes  backwards,  downwards,  and  medially,  and 
may  compress  the  innominate  vein,  the  trachea,  or  on  the  left  side,  the 
oesophagus. 

Dislocation  upwards  is  especially  resisted  by  the  articular  disc  and  the 
inter-clavicular  ligaments.  When  these  ligaments  are  torn,  the  sternal 
end  of  the  clavicle  passes  into  the  jugular  (supra-sternal)  notch  between  the 
sterno-mastoid  anteriorly  (p.  8)  and  the  sterno-hyoid  and  sterno-thyreoid 
posteriorly. 

The  sterno-clavicular  joint  is  not  infrequently  the  seat  of  suppuration 
in  pyaemia.  One  or  both  compartments  may  be  involved  and  the  pus  usually 
perforates  the  anterior  ligament.  Should  it  perforate  the  posterior  ligament, 


io  THE  SUPERIOR  EXTREMITY 

it  will  find  its  way  down  between  the  two  pleural  sacs  into  the  superior 
mediastinum,  following  the  course  of  the  innominate  vein. 

On  the  right  side,  the  joint  may  be  involved  in  aneurism  of  the  innominate 
artery,  which  lies  immediately  behind  it. 

Acromio- Clavicular  Joint.— The  articular  surfaces  of 
the  two  bones  are  oblique  and  the  plane  of  the  joint  passes 
downwards  and  medially.  A  weak  capsule,,  thickened  above 
and  below,  is  attached  to  the  articular  margins.  A  wedge- 
shaped  disc  protrudes  into  the  joint  cavity  from  the  upper 
part  of  the  capsule  ;  the  disc  is  covered  and  the  capsule  is  lined 
with  synovial  membrane.  The  joint  is  strengthened  by  the 
accessory  conoid  and  trapezoid  bands,  which  together  form  the 
coraco  -  clavicular  ligament  and  bind  the  upper  surface  of 
the  coracoid  process  to  the  under  surface  of  the  clavicle  near  its 
acrornial  end.  Part  of  the  weight  of  the  upper  limb  is  conveyed 
to  the  clavicle  along  this  ligament. 

The  posterior  supra-clavicular  (supra-acromial)  nerves  (C.  3 
and  4)  and  the  acromial  branch  of  the  thoraco-acromial  artery 
(p.  30)  supply  the  joint. 

A  gliding  antero-posterior  movement  occurs  at  the  acromio- 
clavicular  articulation,  so  that,  when  the  shoulder  is  thrust 
forwards,  the  angle  between  the  clavicle  and  the  upper  border 
of  the  spine  of  the  scapula  becomes  smaller. 

The  obliquity  of  the  articular  surfaces  serves  to  explain  the 
common  injury  of  upward  dislocation  of  the  clavicle.  Any  force 
directed  medially  or  downwards  on  to  the  acromion  will  thrust 
it  beneath  the  clavicle,  tearing  the  superior  ligament  of  the 
joint.  The  reverse  dislocation  is  extremely  rare.  A  much 
exaggerated  displacement  in  either  dislocation  indicates  rupture 
of  the  coraco-clavicular  ligament. 

The  Clavicle  fulfils  the  functions  of  a  prop  and  keeps  the 
acromion,  and,  through  it,  the  shoulder-joint  at  a  constant 
distance  from  the  trunk,  to  which  it  transmits  the  weight  of  the 
upper  limb.  The  trapezius  supports  its  acromial  end  and 
counteracts  the  downward  pull  of  the  weight  of  the  arm.  The 
clavicle  is  exposed  more  often  to  violence  than  any  other  bone 
in  the  body  and,  for  that  reason,  is  very  commonly  injured. 
These  injuries  may  take  the  form  of  fractures,  dislocations,  or 
separation  of  the  epiphysis. 

Ossification. — The  clavicle  is  the  first  bone  in  the  body  to  ossify  (fifth 
week),  and  the  primary  centre  forms  the  shaft  and  the  acromial  end.  A 
secondary  centre  appears  at  the  sternal  end  at  about  the  twentieth  year 
and  fuses  with  the  shaft  about  the  twenty-fifth.  Congenital  absence  of  both 


THE  SHOULDER  REGION  n 

clavicles  is  rare,  but  from  accounts  of  the  recorded  cases,  the  functional 

disability  is  slight. 

Excision  of  the  Clavicle. — Removal  of  the  Middle  Third 
of  the  clavicle  is  commonly  carried  out  as  a  preliminary  step 
in  interscapulo-thoracic  amputation,  as  it  facilitates  ligature  of 
the  third  part  of  the  subclavian  artery.  The  Whole  Bone 
may  be  excised  most  easily  from  acromial  to  sternal  end. 

Examination  of  the  Clavicle. — In  suspected  injury  of  the 
clavicle  or  of  the  acromion,  the  surgeon  stands  behind  the  patient 
and  compares  the  contours  of  the  two  shoulders.  He  next 
places  a  hand  on  each  side  of  the  neck  in  such  a  way  that  the 
tips  of  the  fingers  palpate  the  jugular  (supra-sternal)  notch 
and  the  thumbs  rest  behind  on  the  vertebral  spines.  The  hands 
are  separated  from  one  another  so  that  the  fingers  pass  over  the 
subcutaneous  surfaces  of  the  two  clavicles.  When  the  acromio- 
clavicular  joint  is  reached  the  fingers  are  carried  forwards  around 
the  anterior  extremity  of  the  acromion,  and  its  subcutaneous 
surface  and  lateral  border  may  be  palpated. 

Fractures  of  the  Clavicle. — Fracture  of  the  sternal  end  of 
the  clavicle,  medial  to  the  costo-clavicular  (rhomboid)  ligament,, 
is  rare,  and  the  displacement  is  not  great  unless  the  costo- 
clavicular  ligament  is  torn.  When  this  occurs,  the  medial 
end  of  the  lateral  fragment  is  drawn  upwards  by  the  sterno- 
mastoid  and  the  acromial  end  of  the  clavicle  sinks  downwards 
owing  to  the  weight  of  the  arm. 

The  common  site  of  fracture  is  the  point  of  union  of  the  middle 
and  lateral  thirds,  where  the  bone  is  weak  owing  to  the  junction 
of  its  two  curves.  It  is  the  commonest  of  all  fractures.  One 
third  of  the  cases  are  of  the  greenstick  variety  and  occur  in 
infancy.  It  is  generally  due  to  indirect  violence  from  falls  on 
the  hand,  elbow,  or  shoulder,  and  the  force  is  transmitted  to 
the  clavicle  through  the  glenoid  cavity  and  the  coraco-clavicular 
ligament,  or  through  the  acromion.  The  direction  of  the 
fracture  is  most  constant — it  is  downwards,  medially,  and 
forwards.  The  displacement  of  the  lateral  fragment  is  in  the 
same  direction,  and  the  limb  collapses  medially  and  forwards 
on  to  the  trunk,  consequent  on  the  snapping  of  its  prop.  The 
medial  fragment  is  drawn  upwards  by  the  sterno-mastoid.  It 
is  rare  to  find  any  injury  to  the  subclavian  vessels  or  to  the 
nerves  of  the  brachial  plexus,  which  all  lie  behind  and  below 
the  clavicle,  because  they  are  protected  by  the  subclavius 
muscle,  which  acts  as  a  cushion  between  them  and  the  broken 


12  THE  SUPERIOR  EXTREMITY 

bone.  Occasionally,  the  lateral  fragment  is  displaced  backwards 
by  direct  violence  from  in  front.  In  this  case  the  transverse 
scapular  (supra-scapular)  and  transverse  cervical  (transversalis 
colli)  veins  (p.  131)  may  be  injured. 

Fracture  of  the  acromial  end  of  the  shaft  may  occur  between 
the  attachments  of  the  two  parts  of  the  coraco-clavicular 
ligament  from  direct  violence,  in  which  case  there  is  little 
displacement,,  or  it  may  occur  lateral  to  the  ligament,  in  which 
case  the  lateral  fragment  tends  to  turn  medially  and  forwards. 
The  point  of  the  shoulder  is  rotated  medially  and  sinks  slightly. 

In  children,  fractures  of  the  clavicle  are  usually  of  the 
greenstick  variety,  as  the  bone  is  soft  and  its  enveloping 
periosteum  is  exceedingly  strong. 

The  Vertebro-Scapular  Muscles.  —  The  Trapezius  is  described  on 
p.  6. 

The  Levalor  Scapulce  is  attached  to  the  medial  (superior)  angle  of  the 
scapula,  by  elevating  which  it  helps  to  depress  the  point  of  the  shoulder. 
It  is  supplied  by  C.  3  and  4  (p.  130). 

The  Rhomboid  Minor  and  Major  arise  from  the  upper  thoracic  spines 
and  are  inserted  into  the  vertebral  border  of  the  scapula.  They  draw  the 
scapula  medially,  backwards  and  upwards.  The  dorsalis  scapulae  nerve 
(nerve  to  the  rhomboids)  (C.  5)  runs  down  along  the  vertebral  border  of  the 
scapula  under  cover  of  the  three  above-mentioned  muscles.  (The  results  of 
injury  to  this  nerve  are  described  on  p.  97.)  It  is  accompanied  by  the 
descending  (posterior  scapular)  branch  of  the  transverse  cervical  artery, 
which  anastomoses  on  the  scapula  with  the  subscapular  (p.  34)  and  the 
transverse  scapular  (supra-scapular)  arteries  (p.  143). 

The  Scapula. — Ossification  begins  in  the  fcetal  scapula 
during  the  second  month.  The  most  important  secondary 
centre  forms  the  greater  part  of  the  coracoid  process.  It 
appears  during  the  first  year  and  joins  the  body  about  the 
eighteenth  year.  Cases  of  ununited  coracoid  epiphyses  have 
been  recorded,  but  the  condition  is  very  rare. 

Two  secondary  centres  appear  about  the  tenth  year  to  form 
the  acromion,,  and  join  the  spine  of  the  scapula  about  twenty-five. 
This  epiphysis  fails  to  fuse  in  10  per  cent  of  subjects,  and  the 
condition  is  usually  bilateral.  The  line  of  non-union  is  transverse 
and  is  at  right  angles  to  the  axis  of  the  acromio-clavicular  joint. 
The  acromion  is  generally  attached  to  the  spine  by  fibrous 
tissue,  but  occasionally  a  complete  joint  is  present.  The  presence 
of  a  movable  acromion,  together  with  a  history  of  injury  to 
the  shoulder  region,  is  apt  to  suggest  a  fracture.  The 
symmetrical  character  of  ununited  acromial  epiphysis  is  of 
great  value  in  the  differential  diagnosis. 


THE  SHOULDER  REGION  13 

A  sub-coracoid  centre,,  which  forms  part  of  the  base  of  the 
coracoid  and  the  upper  part  of  the  glenoid  cavity,  appears  at 
ten  and  fuses  at  seventeen.  The  margin  of  the  glenoid  cavity 
inferiorly  is  formed  by  a  secondary  centre  which  appears  at 
seventeen  and  fuses  soon  after.  The  other  secondary  centres 
have  little  surgical  importance. 

Fractures  of  the  Scapula  are  uncommon  because  the  bone 
is  well  protected  by  muscles.  The  commonest  variety  is 
fracture  of  the  body,  generally  through  the  infra-spinous  fossa. 
The  spine  and  coracoid  process,  which  belong  to  the  upper 
fragment,  may  be  gripped  with  one  hand,  and  the  inferior 
angle,  which  belongs  to  the  lower  fragment,  with  the  other. 
Preternatural  mobility  and  crepitus  may  be  determined  by 
moving  the  hands  in  opposite  directions. 

If  the  surgical  neck,  which  extends  from  the  scapular  notch 
to  a  point  on  the  axillary  border  just  below  the  glenoid  cavity, 
is  fractured,  the  surgeon  can  grasp  the  spine  and  acromion  with 
one  hand  and  the  head  of  the  humerus  with  the  other.  Crepitus 
may  sometimes  be  elicited,  through  the  medium  of  the  capsule 
of  the  shoulder-joint,  by  moving  the  head  of  the  humerus 
backwards  and  forwards. 

Fracture  of  the  Coracoid  is  rare,  and  up  to  seventeen  may 
l)e  of  the  nature  of  a  separation  of  the  epiphysis.  There  is  little 
displacement,  unless  the  coraco -clavicular  ligament,  which 
holds  it  up,  is  torn.  Laterally,  the  coracoid  is  steadied  by  the 
coraco-acromial  ligament,  and  medially,  by  the  pectoralis  minor. 
It  is  drawn  downwards  by  the  weight  of  the  arm  and  by  the 
coraco-brachialis  and  the  short  head  of  the  biceps,  which  are 
attached  to  its  tip. 

In  complete  excision  of  the  scapula  for  malignant  disease,  a 
preliminary  ligature  of  the  subscapular  vessels  and  myotomy 
of  the  muscles  attached  to  the  coracoid  process  may  be  performed 
through  an  incision  along  the  medial  border  of  the  coraco- 
brachialis. 

The  Coraco-Acromial  Ligament  passes  from  the  lateral 
border  of  the  coracoid  process  to  the  acromion  just  in  front  of 
the  acromio-clavicular  joint.  It  forms  a  strong  arch  above 
the  shoulder-joint,  and  helps  to  prevent  upward  dislocation  of 
the  head  of  the  humerus. 

The  Sub-acromial  Bursa  lies  between  the  deltoid,  the 
acromion  and  the  coraco-acromial  ligament  above,  and  the 
capsule  of  the  shoulder-joint  and  the  muscles  attached  to  it 


14  THE  SUPERIOR  EXTREMITY 

below.  It  very  rarely  communicates  with  the  joint,  but  owing 
to  its  position,  pathological  conditions  of  the  bursa  may  be 
mistaken  for  articular  affections.  The  sub-acromial  bursa 
serves  as  a  soft  pad  between  the  humerus  and  the  acromion, 
but  when  it  is  distended  with  fluid  or  when  the  walls  are 
thickened  by  chronic  inflammation  (Codman's  bursitis), 
movements  of  the  humerus  become  painful,  especially  the 
movement  of  abduction,  which  crushes  up  the  bursa  against 
the  acromion.  Pus  from  an  abscess  of  this  bursa  gravitates 
either  to  the  anterior  or  to  the  posterior  border  of  the  deltoid. 

The  Deltoid  (p.  3)  continues  and  maintains  the  movement 
of  abduction  of  the  humerus,  after  it  has  been  initiated  by  the 
supra-spinatus.  In  complete  abduction  the  humerus  can  be 
raised  to  an  angle  of  nearly  180°,  but  the  deltoid  is  responsible 
for  only  half  of  that  amount.  The  rest  is  effected  by  rotation 
of  the  scapula  under  the  action  of  the  trapezius  and  the  serratus 
anterior  (p.  31).  The  clavicular  fibres  are  flexors  and  medial 
rotators  of  the  humerus  ;  the  posterior  fibres  have  the  opposite 
actions.  The  muscle  overlies  the  shoulder- joint  and  the  tendons 
in  relation  to  it,  and  is  supplied  by  the  axillary  (circumflex) 
nerve  (C.  5  and  6),  which  enters  its  deep  surface. 

The  Deep  Fascia  on  the  Dorsal  Scapular  Muscles. — The 
deep  fascia  is  strong  and  dense  over  the  supra-spinatus  and 
infra-spinatus  muscles,  and  is  attached  to  the  borders  of  the 
scapular  fossae.  It  is  weakened  above  the  superior  transverse 
scapular  (supra-scapular)  ligament,  where  the  transverse  scapular 
vessels  enter  the  fossa,  and  also  at  a  point  half-way  down  the 
axillary  border,  where  the  circumflex  scapular  (dorsalis  scapulae) 
vessels  pass  on  to  the  dorsum. 

Pus  originating  in  the  infra-spinous  fossa  is  prevented  from 
passing  backwards  by  the  strong  fascia.  It  follows  the  circumflex 
scapular  (dorsalis  scapulae)  vessels  and  gravitates  down  to 
point  at  the  lower  part  of  the  posterior  fold  of  the  axilla.  In 
the  supra-spinous  fossa  it  generally  passes  through  or  over  the 
scapular  (supra-scapular)  notch  and  points,  near  the  coracoid 
process,  under  the  anterior  border  of  the  deltoid  ;  or,  it  may 
gravitate  into  the  infra-spinous  fossa  :  or,  very  rarely,  it  may 
make  its  way  through  the  supra-spinous  fascia  and  the  trapezius 
and  point  in  the  angle  between  the  clavicle  and  the  spine  of  the 
scapula. 

The  Supra-spinatus  arises  from  the  supra-spinous  fossa,  and  is  inserted 
into  the  upper  surface  of  the  greater  tubercle  of  the  humerus.  It  passes 


THE  SHOULDER  REGION  15 

immediately  above  the  shoulder-joint  and  is  partly  inserted  into  the  capsule. 
It  initiates  the  movement  of  abduction  and  assists  the  deltoid. 

The  Infra-spinatus  arises  from  the  infra-spinous  fossa,  and  is  inserted 
into  the  postero-superior  surface  of  the  greater  tubercle.  It  passes  over  the 
posterior  surface  of  the  shoulder-joint  and  partially  blends  with  the  capsule  ; 
it  is  the  chief  lateral  rotator  of  the  humerus. 

Both  these  muscles  are  supplied  by  the  supra-scapular  nerve  (C.  5  and  6), 
which  passes  through  the  scapular  notch  below  the  ligament.  (The  results 
of  injury  to  this  nerve  are  described  on  p.  98.) 

The  Teres  minor  lies  in  relation  to  the  posterior  aspect  of  the  capsule 
of  the  shoulder-joint,  and  its  action  is  the  same  as  that  of  the  infra-spinatus. 
It  is  supplied  by  the  axillary  (circumflex)  nerve  (C.  5  and  6). 

Ossification  of  the  Proximal  Extremity  of  the  Humerus.— 

At  birth  the  proximal  extremity  of  the  humerus  is  entirely 
cartilaginous.  During  the  first  year  a  secondary  centre  appears 
for  the  articular  head  of  the  bone ;  at  the  second  year,  one 
appears  for  the  greater  tubercle ;  at  the  end  of  the  third  year, 
one  appears  for  the  lesser  tubercle.  These  three  centres  unite 
to  form  the  proximal  epipbysis  of  the  humerus  during  the 
seventh  year.  It  fits  like  a  cap  over  the  proximal  end  of  the 
diaphysis,  which  is  somewhat  pointed  (Fig.  5),  and  it  fuses 
with  the  diaphysis  between  eighteen  and  twenty-five.  The 
epiphyseal  line  passes  distal  to  the  tubercles,  but  on  the  medial 
side  it  coincides  with  the  margin  of  the  articular  head  of  the  bone. 

Ossification  of  glenoid  cavity  (p.  13). 

The  Shoulder-Joint.— The  articular  surface  of  the  glenoid 
cavity  is  slightly  concave  and  is  small  in  comparison  with  the 
head  of  the  humerus,  which  forms  a  large  convex  surface, 
directed  upwards,  medially,  and  slightly  backwards.  The 
glenoid  cavity  is  enlarged  and  deepened  by  the  labrum  glenoidale 
(glenoid  ligament),  which  is  attached  to  its  margins. 

The  Capsule,  which  is  very  large  and  remarkably  loose, 
obtains  a  wide  range  of  movement  for  the  joint.  Proximally, 
it  is  attached  to  the  labrum  glenoidale,  and  above,  to  the  bone 
immediately  beyond  the  origin  of  the  long  head  of  the  biceps. 
On  the  humerus  it  is  attached  to  the  anatomical  neck,  laterally, 
but  to  the  surgical  neck,  on  the  medial  side.  The  line  of 
attachment  of  the  capsule  crosses  the  epiphyseal  line,  so  that 
the  lateral  portion  of  the  epiphysis  (the  tuber osities)  is  extra-capsutar , 
while  the  medial  part  of  the  proximal  end  of  the  diaphysis  is 
intra-capsular. 

The  capsule  is  strengthened  anteriorly  by  the  three  gleno- 
humeral  ligaments,  and  above  by  the  coraco-humeral  ligament. 
These  accessory  bands  blend  with  the  capsule  so  closely  that 


i6 


THE  SUPERIOR  EXTREMITY 


it  is  impossible  to  separate  them  from  it.  Additional  support 
is  received  from  the  subscapularis  in  front,  the  supra-spinatus 
above,  and  the  infra-spinatus,  and  to  a  lesser  degree  the  teres 


FIG.  5. — Shoulder  of  a  Child,  aged  six.  Antero-posterior  view.  The  centre 
of  ossification  for  the  greater  tubercle  has  not  yet  fused  with  the  centre 
for  the  head  of  the  humerus.  The  radiogram  shows  a  fracture  through 
the  surgical  neck  of  the  bone.  Compare  the  position  of  the  head  of  the 
humerus  with  that  shown  in  Fig.  7. 

minor,  behind.  Inferiorly,  the  capsule  pouches  downwards 
when  the  arm  is  by  the  side,  an  arrangement  which  permits  of 
free  abduction.  It  is  here  intimately  related  to  the  quadrilateral 


THE  SHOULDER  REGION 


space  (p.  39),  and  the  structures  passing  through  it  (Fig.  6). 
Stiffness  of  the  shoulder,  following  reduction  of  dislocations, 
may  be  due  to  the  formation  of  adhesions  between  the  contiguous 
synovial  surfaces  of  this  part  of  the  capsule.  Early  massage 
and  passive  movement  will  prevent  such  a  complication. 


Capsule 


Epiphyseal  line 


Sub-acromial  bursa 
Acromion 
i  Clavich 


Tendon  of  bicep 


Joint  cavity 


Synovial 

sheath  of 

biceps 

tendon 


Proximal  epi- 
physis  of 
humerus 
Labrum 
glenoidale 


_*f^^^  Epiphyseal  line 
(sub-coracoid) 


Epiphyseal  line 
(glenoid) 

Dependent  part 
of  capsule 
Axillary  nerve 


FIG.  6. — Frontal  Section  through  the  Right  Shoulder-Joint.  The  parietal 
and  visceral  layers  of  the  synovial  sheath  of  the  biceps  tendon  have  been 
partially  left  in  place. 

Light  blue  =  articular  cartilage.          Green  —  periosteum. 

Dark  blue  =  ligaments.  Red  — synovial  membrane. 

The  Synovial  Membrane  lines  the  capsule  and  is  attached 
to  the  articular  margins  of  the  two  bones.  It  covers,  but  is 
not  adherent  to,  the  periosteum  over  the  intra-capsular  part, 
of  the  neck  of  the  humerus  (intra-capsular  part  of  diaphysis 
and  epiphyseal  cartilage,  in  the  young).  Between  the  superior 

2 


1 8  THE  SUPERIOR  EXTREMITY 

and  middle  gleno-humeral  ligaments,  there  is  an  opening  in  the 
capsule.  The  synovial  membrane  of  the  joint  herniates  through 
this  opening  to  form  a  bursa,  which  is  situated  between  the 
subscapularis  in  front  and  the  neck  of  the  scapula  and  the 
capsule  behind.  A  similar  bursa,  communicating  with  the 
joint,  may  occasionally  be  found  between  the  capsule  and  the 
tendon  of  the  infra-spinatus. 

The  long  head  of  the  biceps  arises  from  the  highest  point  on 
the  glenoid  margin  and  traverses  the  joint.  But  although  it 
is  intra-capsular,  it  remains  extra-synovial  as  it  receives  a  tubular 
sheath  from  the  synovial  membrane  (Fig.  6),  which  invests 
the  tendon  for  a  varying  distance  after  it  has  left  the  capsule. 
This  synovial  sheath  and  the  tendon  are  retained  in  the  inter- 
tubercular  sulcus  by  the  transverse  ligament  —  a  special  slip 
of  the  capsule,  which  bridges  the  groove  and  is  attached  to 
both  tubercles.  This  ligament  is  occasionally  torn  by  violent 
muscular  efforts,,  and  when  that  occurs  the  tendon  of  the  biceps 
becomes  displaced  to  the  medial  side  of  the  lesser  tubercle. 
Until  the  tendon  is  replaced  by  the  movement  of  abduction,, 
the  forearm  cannot  be  completely  extended  (Thomson  and 
Miles). 

The  nerve-supply  of  the  joint  comes  from  the  supra-scapular 
and  axillary  (circumflex)  nerves  (C.  5  and  6). 

Around  the  surgical  neck  of  the  humerus  an  arterial  ring 
is  formed  by  the  anterior  and  posterior  circumflex  arteries,  which 
send  branches  proximally  to  supply  the  joint.  These  anastomose 
with  twigs  from  the  transverse  scapular  (supra-scapular),  which 
descend  from  above,  and  with  an  ascending  branch  from  the 
(superior)  profunda  (p.  43). 

The  presence  of  fluid  within  the  joint  may  be  appreciated 
in  the  neighbourhood  of  the  long  head  of  the  biceps,  because 
it  gravitates  down  the  synovial  sheath  which  surrounds  the 
tendon.  When  the  subscapularis  bursa  is  involved,  the  swelling 
may  be  felt  high  up  on  the  posterior  wall  of  the  axilla.  The 
joint  is  best  aspirated  by  pushing  the  needle  backwards  through 
the  deltoid  and  the  subscapularis  at  a  point  a  quarter  of  an  inch 
medial  to  the  lesser  tubercle,  which  serves  as  a  convenient  bony 
landmark.  In  this  way  the  great  vessels  and  nerves  and  the 
sub-acromial  bursa  are  all  avoided. 

Spread  ot  Tuberculous  Disease  in  the  Shoulder  Region.— 
When  tuberculous  disease  originates  in  the  head  or  neck  of  the 
scapula,  it  readily  spreads  to  the  joint  through  the  articular 


THE  SHOULDER  REGION  19 

cartilage,  because  the  epiphyseal  cartilages  of  the  secondary 
centres  for  the  glenoid  cavity  only  exist  near  its  margin  (p.  13). 

If  the  disease  begins  in  the  proximal  end  of  the  diaphysis  of 
the  humerus  and  spreads  either  forwards,  backwards,  or  laterally, 
it  will  in  time  perforate  the  periosteum  and  infect  the  overlying 
soft  parts.  Should  it  spread  medially,  it  will  perforate  the 
periosteum  covering  the  intra-capsular  part  of  the  diaphysis 
(Fig.  6).  The  infection  will  then  be  intra-capsular  but  extra- 
synovial.  The  synovial  membrane  rapidly  becomes  involved 
and  the  joint  infected.  If  the  disease  spreads  upwards,  it  must 
involve  the  epiphyseal  cartilage  and  epiphysis  before  it  can 
break  through  the  articular  cartilage  into  the  joint.  Lastly, 
it  may  travel  distally  and  infect  the  medullary  cavity. 

Surgical  Approach  to  the  Shoulder- Joint. — In  Empycema 
of  the  joint,  good  access  is  obtained  by  a  vertical  incision, 
made  midway  between  the  coracoid  process  and  the  acromion. 
The  anterior  fibres  of  the  deltoid  are  divided  and  the  dis- 
tended capsule,  which  is  then  exposed,  can  be  incised.  A 
pair  of  dressing  forceps  may  be  passed  through  the  joint  and 
made  to  project  posteriorly  below  the  tendon  of  the  teres 
minor.  The  instrument  may  then  be  cut  down  upon  from 
behind  and  a  drainage  tube  drawn  through. 

In  Tuberculous  Disease,  the  joint  may  be  approached  either 
from  the  anterior  or  from  the  posterior  aspect.  The  latter 
route,  though  more  difficult,  gives  the  better  access  (Kocher). 
In  the  anterior  method  the  approach  is  direct,  and  little  damage 
is  done  either  to  the  deltoid  or  to  its  nerve  of  supply.  By 
rotating  the  humerus  first  medially  and  then  laterally,  it  is 
possible  to  elevate  the  muscles  from  the  greater  and  lesser 
tubercles,  either  sub-periosteally  or  sub-cortically,  depending 
on  the  age  of  the  patient.  The  head  of  the  humerus  may  be 
removed  through  a  comparatively  small  incision,  but  if  the 
glenoid  cavity  and  neck  of  the  scapula  require  to  be  excised, 
some  difficulty  will  be  found  in  removing  them  by  the  anterior 
method  of  approach. 

The  posterior  method  of  approach  affords  a  much  more 
extensive  view  of  the  articulation.  This  is  obtained  by  freeing 
the  trapezius  and  the  deltoid  from  the  spine  of  the  scapula,  by 
sawing  through  the  spine  obliquely  into  the  great  scapular 
notch,  and  by  rotating  forwards  the  acromion  and  the  deltoid. 
The  capsule  is  opened  above,  where,  according  to  Kocher,  the 
subsequent  weakness  matters  least. 


20  THE  SUPERIOR  EXTREMITY 

Dislocation  of  the  Shoulder.— In  the  child,  the  capsule 
is  stronger  than  the  bond  of  union  between  the  diaphysis  and 
epiphysis,  and  consequently  the  common  injury  is  a  separation 
of  the  proximal  epiphysis.  In  the  adult,  the  shoulder-joint  is 
ligamentously  and  osseously  weak,  and  is  strong  only  by  virtue 
of  its  muscular  support.  Stability  is  sacrificed  to  the  necessity 
for  mobility,  and,  as  a  result,  dislocation  of  the  joint  is  exceedingly 
common. 

The  violence  which  causes  the  dislocation  is  unexpected, 
and  the  supporting  muscles  are  consequently  relaxed  at  the 
time  of  the  accident.  The  humerus  is  generally  in  the  abducted 
position  and  forms  the  long  arm  of  a  lever,  whose  short  arm  is 
formed  by  the  head  of  the  bone.  The  acromion  acts  as  a  fulcrum, 
and  when  the  long  arm  of  the  lever  is  thrust  upwards,  the  head 
is  tilted  downwards  upon  the  inferior  part  of  the  capsule,  which 
is  the  only  area  unsupported  by  muscular  insertions.  This 
gives  way,  and  the  head  of  the  bone  passes  through  the  tear 
and  lies  below  the  glenoid  cavity. 

The  head  may  remain  in  this  position — the  sub-glenoid 
dislocation.  The  lower  margin  of  the  glenoid  rests  in  the  groove 
of  the  anatomical  neck,  and  the  head  lies  between  the  long  head 
of  the  triceps  behind  and  the  subscapularis  in  front. 

Though  all  dislocations  are,  in  the  first  instance,  sub-glenoid, 
the  flexors  and  adductors  of  the  shoulder  usually  draw  the  head 
of  the  humerus  upwards,  forwards,  and  medially.  This  is  the 
anterior  displacement,  and  the  head  of  the  bone  may  occupy 
any  of  the  following  positions  : 

1.  The  Sub-coracoid. — This  is  the  commonest  dislocation. 
The  posterior  part  of  the  anatomical  neck  rests  against  the 
anterior  margin  of  the  glenoid  cavity,  and  the  head  lies  behind 
the  subscapularis.    The  articular  surface  is  directed  somewhat 
forwards,  and  the  humerus  is  laterally  rotated  owing  to  the 
stretching   of  the  infra-spinatus  and  the  teres   minor.    The 
posterior  part  of  the  capsule  is  stretched  across  the  articular 
surface  of  the  glenoid  cavity. 

2.  The  Intra-coracoid. — In  this  dislocation  the  anatomical 
neck  rests  on  the  anterior  surface  of  the  neck  of  the  scapula. 
The  lateral  rotators  are  over-stretched,  and  if  they  do  not  rup- 
ture, a  part  or  the  whole  of  the  greater  tubercle  is  torn  away, 
and  the  subscapularis,  being  unopposed,  rotates  the  humerus 
medially. 

3.  The   Sub-clavicular. — The  head   of  the  humerus   rests 


THE  SHOULDER  REGION 


21 


on  the  subscapular  fossa,  and  it  can  reach  this  position  only 
after  extensive  laceration  of  the  capsule  and  the  muscles. 


FIG.  7. — Sub-coracoid  dislocation  of  Shoulder- Joint  in  an  Adult  Female. 
Owing  to  the  displacement  the  acromion  projects  beyond  the  greater 
tubercle,  while  the  shadows  thrown  by  the  glenoid  fossa  and  the  upper 
part  of  the  axillary  border  of  the  scapula  are  partially  obscured  by  the 
head  of  the  humerus,  above  which  the  foreshortened  coracoid  process 
can  be  recognised. 

In  the  Posterior  Displacements  the  head  of  the  humerus 


22  THE  SUPERIOR  EXTREMITY 

rests  on  the  posterior  margin  of  the  glenoid  cavity,  or  on  the 
neck  of  the  scapula,  or  in  the  infra-spinous  fossa.  The 
infra-spinatus  is  usually  stripped  up  by  the  head  of  the  bone, 
and  the  nature  of  the  rotation  of  the  humerus  depends  on 
whether  the  subscapularis  is  ruptured  or  remains  intact. 

In  all  dislocations  of  the  shoulder  the  normal  rounded  contour 
is  lost,  as  the  greater  tubercle  is  drawn  medially.  For  the 
same  reason  the  lateral  border  of  the  acromion,  now  the  most 
lateral  bony  point  in  the  region,  becomes  more  prominent,  and  a 
straight  edge  can  be  made  to  touch  both  the  acromion  and  the 
lateral  epicondyle  of  the  humerus.  In  the  anterior  displacements 
the  head  of  the  humerus  produces  a  rounded  elevation,  which 
may  occlude  the  superficial  infra-clavicular  triangle.  This 
deformity  is  more  pronounced  in  the  sub-clavicular  variety. 

Miller's  Method  of  Reduction. — The  initial  steps,  which 
consist  of  abduction  and  traction  on  the  arm,  draw  the  head 
of  the  humerus  free  from  the  scapula,  relax  the  deltoid  and 
supra-spinatus,  and  stretch  the  lower  part  of  the  capsule  and 
the  subscapularis.  If  the  tear  involves  the  anterior  part  of 
the  ligament,  reduction  may  occur  without  further  manipulation, 
as  in  Kocher's  method  (vide  infra).  If  the  tear  is  confined  to 
the  inferior  aspect  of  the  capsule,  the  articular  head  of  the 
humerus  is  brought  into  contact  with  it  by  the  next  step — 
medial  rotation.  Owing  to  the  continued  traction  the  tendon 
of  the  subscapularis  is  tightly  stretched  over  the  head,  which  it 
presses  through  the  gap  when  the  traction  is  lessened.  In  this 
method  an  assistant  steadies  the  patient's  chest  and  scapula 
throughout,  thus  exerting  counter-extension. 

Kocher's  Method  of  Reduction. — In  the  first  instance  the 
patient's  elbow  is  pressed  firmly  against  his  side  in  order  to 
fix  the  distal  end  of  the  humerus,  as  only  by  this  means  can 
subsequent  manipulations  exert  their  full  action  on  the  head 
of  the  bone.  Grasping  the  patient's  wrist  with  his  free  hand, 
the  surgeon  uses  the  forearm  as  a  lever  to  produce  lateral 
rotation  of  the  humerus.  This  is  effected  by  carrying  the  fore- 
arm away  from  the  body  till  it  is  nearly  in  the  frontal  (coronal) 
plane,  and  the  movement  is  performed  slowly  and  steadily  in 
order  to  overcome  the  muscular  spasm.  In  this  way  the 
anatomical  neck  is  disengaged  from  the  glenoid  margin,  and 
the  posterior  aspect  of  the  greater  tubercle  comes  into  contact 
with  the  articular  surface  of  the  glenoid  cavity,  from  which  it  is 
separated  by  a  part  of  the  capsule. 


THE  SHOULDER  REGION  23 

The  articular  head  now  looks  directly  forwards,  and  if  the 
tear  has  spread  to  the  anterior  aspect  of  the  capsule,  the  tendon 
of  the  subscapularis,  rendered  tense  by  the  excessive  lateral 
rotation,  may  press  the  bone  back  into  place. 

If  reduction  does  not  occur  at  this  stage,  the  elbow  is  carried 
forwards  and  medially,  lateral  rotation  of  the  humerus  being 
maintained  through  the  position  of  the  forearm.  This  move- 
ment of  flexion  and  adduction  stretches  the  capsule  by  tilting 
the  greater  tubercle  backwards,  and  at  this  stage  the  head 
often  passes  back  into  place.  Should  it  not  do  so,  the  patient's 
forearm  is  rapidly  swung  over  towards  the  opposite  shoulder 
to  produce  medial  rotation  of  the  humerus.  If  the  elbow  is 
elevated  slightly  during  this  movement,  the  head  of  the  humerus 
descends,  as  it  rotates  medially,  and  passes  through  the  torn 
inferior  part  of  the  capsule. 

In  testing  passive  movements  or  the  limitations  of  movements 
following  injury  in  the  region  of  the  right  shoulder- joint,  the 
surgeon  stands  behind  the  patient  and  holds  the  semi-flexed 
elbow  of  the  affected  side  in  his  own  right  palm.  This  enables 
him  to  move  the  humerus  at  the  shoulder- joint  in  any  way  he 
desires,  while  the  left  hand  examines  the  injured  region.  The 
left  shoulder  is  examined  with  the  positiont>f  the  hands  reversed. 

Complications.  —  Dislocation  of  the  shoulder  may  be 
complicated  by  the  tearing  off  of  a  part  of  the  greater  tubercle. 
If  the  fragment  includes  the  insertion  of  the  supra-spinatus,  it 
is  drawn  upwards  and  subsequently  limits  abduction  by  becoming 
jammed  beneath  the  acromion. 

Fracture  through  the  anatomical  or  surgical  neck  is  a  rare 
but  important  complication.  The  head  of  the  humerus  can  be 
palpated  through  the  superficial  infra-clavicular  triangle  or 
beneath  the  coracoid  process  ;  but  the  diagnosis  of  the  fracture 
will  be  determined  if  movement  of  the  humeral  shaft  produces 
no  effect  on  the  head.  Owing  to  the  small  size  of  the  proximal 
fragment  manipulative  methods  of  reduction  rarely  succeed, 
and  operative  measures  usually  have  to  be  adopted,  the  joint 
being  approached  from  in  front  (p.  19). 

Injuries  to  the  brachial  nerves  following  dislocation  of  the 
shoulder  are  described  on  pp.  98-101. 

Attempts  to  reduce  old-standing  dislocations  of  the  shoulder 
may  cause  rupture  of  the  axillary  artery  and  stretching  or 
laceration  of  the  brachial  plexus,  owing  to  the  presence  of 
adhesions  between  the  head  of  the  humerus  and  the  axillary 


24  THE  SUPERIOR  EXTREMITY 

sheath.  In  these  cases  the  lateral  rotation  carried  out  in 
Kocher's  method  of  reduction  exerts  a  powerful  twisting  or 
spiral  strain  upon  the  bone  and;  if  the  adhesions  are  strong, 
the  humerus  may  be  fractured  spirally  at  the  surgical  neck. 
In  the  old-fashioned  method  of  reduction  by  means  of  the  heel 
in  the  axilla,  the  extending  force  is  exerted  along  the  long  axis 
of  the  shaft  of  the  humerus,  and  there  is  therefore  no  danger  of 
spiral  fracture.  On  the  other  hand,  the  upper  ribs  may  be 
fractured,  unless  the  pressure  of  the  heel  is  directed  towards 
the  coracoid  process  and  not  against  the  chest  wall. 

Congenital  Elevation  of  the  Shoulder.  —  At  an  early  period  of 
development,  the  scapula  and  clavicle  occupy  positions  much  nearer  the  head 
end  of  the  embryo  than  they  do  at  birth,  and  as  the  scapula  grows  in  size 
it  migrates  caudally.  Incomplete  caudal  migration  of  the  scapula  accounts 
for  the  condition  of  congenital  elevation  of  the  shoulder  described  by  Eulen- 
burgh  and  Sprengel.  It  may  be  due  to  the  presence  of  a  bridge  of  bone 
joining  the  vertebral  border  of  the  scapula  to  the  lower  cervical  spines. 
This  bridge  of  bone,  which  may  possess  a  false  joint  at  either  end,  is  homo- 
logous with  the  cartilaginous  supra-scapula  found  in  some  lower  mammals. 

The  upper  border  and  medial  (superior)  angle  of  the  scapula  lie  consider- 
ably above  the  head  of  the  first  rib,  and  may  be  mistaken  for  an  exostosis. 
The  muscles  which  elevate  the  scapula  are  all  definitely  shortened,  and  the 
skin  is  drawn  up  into  a  fold,  which  extends  from  the  mastoid  process  to  the 
acromion.  The  condition  may  be  bilateral  and  is  associated  with  cervical 
ribs,  or  with  faulty  ossification  of  the  cervical  vertebrae,  which  may  be  fused 
together  leading  to  restriction  of  movement. 


THE  BREAST  AND  AXILLA 

Development  of  the  Mammary  Gland.— The  connective 
tissue  of  the  mamma  is  mesodermal  in  origin,  while  the 
glandular  tissue  which  infiltrates  it  is  derived  from  the  ectoderm. 
During  the  second  month  of  embryonic  life  a  distinct  thickening 
of  the  ectoderm  forms  the  mammary  ridge,  which  extends  from 
the  axilla  to  the  groin.  Normally  the  thickening  is  limited 
to  that  part  of  the  ridge  which  subsequently  overlies  the  thorax, 
but  occasionally  it  is  not  so  limited,  and  then  supernumerary 
nipples  or  breasts  may  appear. 

During  the  third  month  the  ectodermal  nodule  becomes 
depressed  or  invaginated  into  the  underlying  connective  tissue 
so  that  a  small  pit  is  formed.  In  the  fifth  month  solid  ectodermal 
buds,  from  fifteen  to  twenty  in  number,  grow  inwards,  and 
their  stalks  subsequently  give  rise  to  the  epithelial  lining  of  the 


THE  BREAST.  AND  AXILLA  25 

lactiferous  ducts.  Extensive  changes  occur  during  the  seventh 
and  the  ninth  months.  The  lobes  derived  from  the  ectodermal 
buds  subdivide  to  form  lobules,  which,  at  their  growing  ends, 
invade  the  surrounding  connective  tissue  and  fat,  thus  breaking 
up  the  mesodermal  stroma  into  the  interlobular  septa  and 
fibrous  framework  of  the  corpus  mammae.  At  the  same  time 
the  whole  ectodermal  mass  becomes  canaliculised  and  gives 
rise  to  a  system  of  ducts  and  alveoli,  while  the  depressed  area 
becomes  evaginated  on  the  surface  to  form  the  nipple.  During 
the  latter  part  of  fcetal  life  the  ampullae  develop  in  the  lactiferous 
ducts,  which  open  on  the  apex  of  the  nipple. 

At  puberty,  the  size  of  the  gland  increases,  owing  to  an 
increase  in  the  parenchyma ;  during  pregnancy,  the  glandular 
tissue  proliferates,  and  the  mamma  reaches  its  full  development ; 
at  the  menopause,  involution  occurs  in  the  more  recently 
developed  portions. 

The  Mammary  Gland  possesses  no  capsule ;  it  consists  of 
a  central  portion  and  of  peripheral  branching  processes  which 
radiate  into  the  surrounding  paramammary  fat  (Stiles).  The 
superficial  fascia,  which  covers  it,  sends  down  fibrous  processes, 
called  the  ligaments  of 'Cooper,  to  join  the  connective  tissue  septa 
which  ramify  throughout  the  gland.  Prolongations  of  the 
parenchyma  of  the  gland  are  found  in  the  ligaments  of  Cooper, 
in  the  loose  retro-mammary  tissue,  and  sometimes  even  in  the 
intervals  between  the  fasciculi  of  the  pectoralis  major.  When 
the  ligaments  of  Cooper  are  invaded  by  malignant  disease, 
they  become  shorter  and  cause  dimpling  of  the  skin,  which,  on 
this  account,  is  no  longer  freely  movable  over  the  breast. 

The  breast  rests  upon  the  pectoral  fascia  and  extends  from 
the  second  rib  above  to  the  sixth  costal  cartilage  below.  At 
the  level  of  the  fourth  rib  it  extends  horizontally  from  the 
lateral  border  of  the  sternum  to  the  fifth  rib  in  the  mid-axillary 
line  (Stiles).  Its  medial  half  rests,  above,  upon  the  pectoralis 
major,  and,  below,  on  the  aponeurosis  of  the  external  oblique 
where  it  covers  the  upper  part  of  the  rectus  abdominis.  Its 
lateral  half  lies  upon  the  pectoralis  major  above,  and  on  the 
serratus  anterior  (s.  magnus)  and  the  external  oblique  (digitations 
of  origin)  below.  Spence's  axillary  tail  is  a  narrow  portion  of 
the  gland,  which  reaches  up  under  cover  of  the  pectoralis  major 
as  far  as  the  third  rib. 

The  arterial  supply  of  the  mammary  gland  is  derived  from 
the  lateral  (long)  thoracic  (p.  31)  and  the  anterior  perforating 


26  THE  SUPERIOR  EXTREMITY 

branches — especially  the  second  and  third — which  arise  from 
the  internal  mammary  in  the  intercostal  spaces  and  pass 
forwards  through  the  pectoralis  major  near  the  margin  of  the 
sternum.  I 

The  Lymph  Vessels  of  the  breast  may  be  divided  into  two 
sets — (i)  the  cutaneous,,  (2)  the  glandular. 

i.  The  cutaneous  lymph  vessels  form  a  plexus  beneath  the 
areola,  and  from  it  the  vessels  extend;  in  the  fibrous  septa  of  the 
subcutaneous  fat,  towards  the  periphery  of  the  breast,  where 
they  join  the  extensive  lymphatic  plexus  in  the  fascia  enveloping 
the  pectoralis  major — the  pectoral  plexus.  (2)  The  glandular 
lymph  vessels,  which  surround  the  alveoli,  lie  in  the  intra-lobular 
connective  tissue  and  communicate  in  front  with  the  cutaneous 
plexus  and  behind  with  the  pectoral  plexus. 

It  is  necessary  to  detail  the  various  connections  of  the 
pectoral  plexus  in  order  that  the  spread  of  malignant  disease, 
both  by  centrifugal  permeation  and  by  embolic  processes,  may 
be  understood.  They  can  be  conveniently  tabulated. 

Connections  of  Pectoral  Plexus. 

1.  With  subscapular  lymph  glands  (p.  35),  which  drain  the  lateral   part 

of  the  plexus. 

2.  With  pectoral  lymph  glands  (p.  35),  which  drain  the  upper  and  lateral 

part  of  the  plexus. 

3.  With  infra- clavicular  lymph  glands  (p.  30),  which  drain  the  upper  part 

of  the  plexus. 

4.  With  the  lymph  glands  which  lie  along  the  internal  mammary  vessels 

in  the  upper  intercostal  spaces,  and  through  them,  with  the  anterior 
mediastinal  lymph  glands,  which  thus  drain  the  medial  part  of  the 
plexus. 

5.  With  the  pectoral  and  cutaneous  plexus  of  the  opposite  side,  across  the 

front  of  the  sternum. 

6.  With  the  sub-peritoneal  plexus  on  the  under  surface  of  the  diaphragm, 

by  communications  which  cross  the  costal  margin,  draining  the 
lower  part  of  the  plexus. 

Mammary  Abscess. —  Superficial  abscess  formation  (pre- 
mammary  abscess)  is  caused  by  organismal  infection  of  the 
cutaneous  lymph  vessels  or  of  the  glands  which  form 
Montgomery's  tubercles. 

If  the  glandular  lymph  vessels  become  involved  by  a  spreading 
infection,  the  abscess  forms  in  the  substance  of  the  breast 
(intra-mammary  abscess).  In  this  case  the  abscess  ramifies 
throughout  the  mamma,  giving  rise  to  loculi,  which  may  be 
traversed  by  fibrous  septa. 


THE  BREAST  AND  AXILLA 


27 


When  the  infection  passes  to  the  pectoral  plexus,  it  gives 
rise  to  an  abscess  behind  the  breast  (retro-mammary  abscess). 
This  variety  more  commonly  arises  from  a  deeper  cause,  such 

Connections  with  pectoral  plexus  of  opposite  side 

Internal  mammary  glands 
Deep  cervical  glands,  postero-inferior  group  [ 

Pectoralis  major,  clavicular  part    I 
Pectoralis  major,  costo-sternal  part 
Apical  glands      i 
Superficial  infra-clavicular  glands  ; 


Central  axillary  glands 

Latissimus  dorsi 


Serratus  anterior  - 
External  oblique 


Connections  with  sub-peritoneal  lymph  plexus 

FIG.  8. — The  Connections  of  the  Pectoral  Lymphatic  Plexus.  The  lymph 
vessels  and  glands  which  lie  deep  to  the  muscles  are  indicated  by  the 
clotted  lines  and  circles. 

as  empysema,  tuberculous  disease  of  a  rib,  etc.,  and  it  tends  to 
push  the  breast  and  the  pectoralis  major  forwards ;  after 
perforating  the  latter,  the  abscess  may  point  in  the  areola  or 
gravitate  towards  the  infra-mammary  groove. 

Incisions  for  the  pre-  and  intra-mammary  abscesses  radiate 


28  THE  SUPERIOR  EXTREMITY 

from  the  nipple,  in  order  to  avoid  injuring  the  lactiferous  ducts. 
If  the  retro-mammary  abscess  is  caused  by  a  forward  spread 
from  deeper  structures,  the  breast  may  be  turned  upwards 
by  a  long  curved  incision  in  the  infra-mammary  groove.  In 
this  way  good  access  is  obtained  and  no  important  structures 
are  injured.  The  same  approach  serves  for  removal  of  the 
breast  in  chronic  mastitis  and  other  simple  conditions. 

THE  AXILLA. — The  axilla  is  the  space  between  the  upper 
part  of  the  chest  wall  and  the  proximal  part  of  the  upper  limb. 
In  shape  it  resembles  a  pyramid  with  a  blunted  apex,  through 
which  the  great  vessels  and  nerves  pass  from  the  root  of  the 
neck  to  the  axilla.  The  apex  is  bounded,  in  front,  by  the 
middle  third  of  the  clavicle,  behind,  by  the  upper  border  of  the 
scapula,  and  medially,  by  the  outer  border  of  the  first  rib. 

Axillary  Fascia. — The  hollo  wed-out  base  of  the  pyramid, 
i.e.  the  floor  of  the  axilla,  is  formed  by  the  axillary  fascia,  which 
is  an  extremely  strong  sheet.  It  is  continuous  in  front  with 
the  fascial  envelope  of  the  pectoralis  major,  and  behind  with 
that  of  the  latissimus  dorsi.  Below,  and  medially,  it  blends 
with  the  fascia  covering  the  serratus  anterior  (magnus),  and 
it  is  continuous  laterally  with  the  deep  fascia  of  the  arm.  Owing 
to  the  great  strength  of  the  axillary  fascia,  abscesses  rarely 
rupture  through  it  spontaneously. 

The  Anterior  Wall  of  the  Axilla  consists  of  two 
strata.  The  Pectoralis  major  and  its  fascia  form  the  superficial, 
and  the  Pectoralis  minor  and  the  clavi-pectoral  fascia  form 
the  deep  layer. 

The  Pectoral  Fascia  closely  envelops  the  pectoralis  major. 
Above,  it  is  attached  to  the  clavicle,  and,  in  its  lateral  part, 
it  forms  the  roof  of  the  superficial  infra-clavicular  triangle. 
Medially,  it  is  attached  to  the  sternum,  and  below  it  is  continuous 
with  the  fascial  covering  of  the  external  oblique  and  the  serratus 
anterior.  Laterally,  it  blends  with  the  axillary  fascia  below 
and  with  the  fascia  of  the  arm  above. 

The  pectoral  fascia  contains  the  efferent  mammary  lymph 
vessels,  and  hence  the  necessity  for  its  exposure  and  removal  in 
cancer  of  the  breast.  The  best  access  to  the  fascia  is  obtained 
by  an  incision  extending  from  the  insertion  of  the  pectoralis 
major  to  the  tip  of  the  eighth  costal  cartilage  of  the  opposite 
side  (Stiles).  This  incision  divides  so  as  to  enclose  the  tumour 
and  an  equally  wide  area  of  skin  and  cutaneous  lymph  vessels 
all  round  it. 


THE  BREAST  AND  AXILLA 


29 


To  expose  the  fascia  completely,  the  skin  above  the  incision 
is  dissected  upwards  and  medially  until  the  clavicle  and  the 
opposite  margin  of  the  sternum  are  visible  ;  the  skin  below  the 
incision  is  undercut  backwards  until  the  level  of  the  posterior 
wall  of  the  axilla  is  reached,  and  downwards  until  the  sheath 
of  the  rectus  abdominis  and  the  upper  digitations  of  the  external 
oblique  are  well  exposed. 

The  Pectoralis  Major  arises  by  a  Clavicular  Head  from  the 
front  of  the  medial  third  or  more  of  the  clavicle  and  by  a  Costo- 
sternal  Head  from  the  front  of  the  sternum,  from  the  aponeurosis 
of  the  external  oblique,  and  from  the  upper  five  or  six  costal 
cartilages.  These  two  heads  of  origin  remain  quite  distinct 
from  one  another  almost  to  the  insertion  into  the  lateral  lip  of 
the  inter-tubercular  sulcus  (bicipital  groove).  The  pectoralis 
major  is  a  powerful  adductor,  and  it  helps  in  flexion  and  medial 
rotation  of  the  humerus.  It  is  supplied  by  the  lateral  and 
medial  anterior  thoracic  nerves  (C.  5,  6,  and  7,  C.  8  and  T.  i). 

If  the  clavicular  head  is  preserved  in  the  operation  of  complete 
excision  of  the  breast,  no  movements  are  lost,  although  the 
arm  is  weakened  by  the  removal  of  the  costo-sternal  portion. 

The  deep  stratum  of  the  anterior  wall  of  the  axilla  is  formed 
by  the  clavi-pectoral  fascia,  the  pectoralis  minor,  and  the 
subclavius. 

The  Pectoralis  Minor  arises  from  the  bony  sternal  extremities 
of  the  third,  fourth,  and  fifth  ribs,  under  cover  of  the  pectoralis 
major,  and  runs  upwards  and  laterally  to  be  inserted  into  the 
medial  border  of  the  coracoid  process.  It  is  supplied  by  the 
medial  anterior  thoracic  nerve  (C.  8  and  T.  i),  from  the  medial 
cord  of  the  brachial  plexus.  The  nerve  pierces  the  muscle 
about  i£  inches  from  its  insertion  and  enters  the  pectoralis 
major.  The  pectoralis  minor  helps  in  forward  and  downward 
movements  of  the  shoulder  girdle ;  and,  when  the  scapula  is 
fixed,  it  acts  as  an  elevator  of  the  ribs. 

The  Subclavius,  which  lies  between  the  clavicle  and  the 
first  rib,  is  supplied  by  a  small  nerve  which  is  formed  by  twigs 
from  C.  5  and  C.  6.  It  helps  to  steady  the  clavicle  in  movements 
of  the  shoulder,  by  pulling  it  medially  towards  the  sternum. 

The  Clavi-Pectoral  Fascia  extends  from  the  clavicle  above 
to  the  axillary  fascia  below.  It  forms  the  fascial  sheath  of  the 
subclavius,  and  is  attached  to  the  edges  of  the  groove  for  that 
muscle  on  the  clavicle.  The  layers  enclosing  the  subclavius 
fuse  at  its  lower  border  to  form  the  costo-coracoid  membrane, 


3° 


THE  SUPERIOR  EXTREMITY 


INNER 


CORD 


which  fills  in  the  gap  in  the  deep  stratum  of  the  anterior  axillary 
wall  between  the  subclavius  above  and  the  pectoralis  minor 
below  (Fig.  9). 

The  Costo-Coracoid  Membrane  is  attached  medially  to 
the  first  costal  cartilage,  laterally  to  the  coracoid  process,  while, 
below,  it  splits  to  enclose  the  pectoralis  minor.  At  its  medial 

end,  it  lies  behind  the  clavi- 
cular head  of  the  pectoralis 
major ;  at  its  lateral  end,  it 
constitutes  the  floor  of  the 
superficial  infra-clavicular 
triangle.  The  infra-clavicular 
lymph  glands  lie  on  its  an- 
terior surface.and  it  is  pierced 
by  the  cephalic  vein  (p.  50), 
the  thoraco-acromial  (thor- 
acic axis)  artery  and  vein, 
and  the  lateral  anterior  thor- 
acic nerve.  The  axillary 
sheath  lies  behind  the  mem- 
brane, separated  from  it  by 
the  loose  fat  and  the  apical 
lymph  glands  of  the  axilla. 
It  is  here  that  the  surgeon 
ligatures  the  first  part  of  the 

FIG.   9.— Diagram  of  a  Section  through    axiHarv    arterv     taking    the 
the  Anterior  Wall  nfthP  Avilla  aXUJOTy    drtery,     taKing 

thoraco-acromial  artery  as 
his  guide. 

At  the  lower  border  of  the 
costo-coracoid  membrane  the 
clavi-pectoral  fascia  splits  to 
enclose  the  pectoralis  minor, 
and  the  layer  on  the  anterior  surface  of  the  muscle  is  intimately 
connected  to  the  fascia  on  the  deep  surface  of  the  pectoralis 
major.  Below  the  pectoralis  minor  the  two  layers  of  the  clavi- 
pectoral  fascia  fuse  to  form  a  single  sheet,  which  passes  down 
to  join  the  axillary  fascia  and  is  termed  the  suspensory  ligament 
of  the  axilla.  This  layer  of  fascia  is  attached  laterally  to  the 
deep  fascia  of  the  arm,  in  front  of  the  great  vessels  and  nerves. 
The  Thoraco-Acromial  (Thoracic  Axis)  Artery  arises  from 
the  second  part  of  the  axillary  artery,  pierces  the  medial 
part  of  the  costo-coracoid  membrane,  close  to  the  upper  border 


the  Anterior  Wall  of  the  Axilla. 

T  A  -r  T  . 

L.A.  f.  Lateral  anterior  thoracic  nerve. 

I.A.T.    Medial  anterior  thoracic  nerve. 

ART.      Axillary  artery,  second  part. 

P.  MA.    Pectoralis  major  muscle. 

P.  Mi.    Pectoralis   minor  muscle,   connected 

by  costo-coracoid  membrane  with 
SCL.        Subclavius  muscle. 
CL.         Clavicle. 


THE  BREAST  AND  AXILLA  31 

of  the  pectoralis  minor  and  breaks  up  into  deltoid  (p.  35), 
acromial  (p.  10),  clavicular  (p.  9),  and  pectoral  branches.  The 
pectoral  branches  pass  downwards  in  the  interval  between 
the  two  pectoral  muscles,  accompanied  by  branches  of  the 
lateral  anterior  thoracic  nerve.  In  excision  of  the  breast, 
haemorrhage  may  be  reduced  by  securing  these  branches  prior 
to  removal  of  the  sternal  portion  of  the  pectoralis  major.  They 
may  be  hooked  up  on  the  forefinger  through  the  interval  between 
the  clavicular  and  sternal  portions  of  the  pectoralis  major 
(p.  3),  as  they  wind  round  the  upper  border  of  the  pectoralis 
minor  (Stiles). 

The  Lateral  (Long)  Thoracic  Artery  passes  from  the 
second  part  of  the  axillary  artery  downwards  and  medially, 
along  the  lower  border  of  the  pectoralis  minor,  to  the  fifth 
intercostal  space.  Its  External  Mammary  branch  reaches  the 
mamma  by  passing  medially  over  the  pectoralis  major. 

The  pectoral  and  infra-clavicular  lymph  glands,  with  their 
efferent  lymph  vessels  from  the  upper  and  lateral  parts  of 
the  pectoral  plexus,  are  so  intimately  connected  with  the 
pectoral  fascia  of  the  anterior  axillary  wall  that  this  wall  is 
usually  removed  in  malignant  disease  of  the  breast.  The  costo- 
sternal  portion  of  the  pectoralis  major  is  divided  near  its  insertion 
and  is  then  reflected  from  its  origin.  As  the  cut  muscle  is 
drawn  forwards  and  laterally,  the  fascia  covering  the  serratus 
anterior  and  the  external  oblique  is  rendered  tense,  and  may 
be  removed  as  a  wide  sheet  as  far  back  as  the  subscapularis. 
It  is  at  this  stage  of  the  operation  that  the  long  thoracic  nerve 
(of  Bell)  is  in  danger,  as  it  runs  down  the  medial  wall  of  the 
axilla  between  the  serratus  anterior  and  its  covering  fascia. 

The  Medial  Wall  of  the  Axilla  is  formed  by  the  upper 
five  ribs  and  external  intercostal  muscles,  partially  covered  by 
the  upper  digitations  of  the  serratus  anterior. 

The  Serratus  Anterior  (S.  magnus)  arises  from  the  lateral 
surfaces  of  the  upper  eight  ribs,  a  short  distance  in  front  of  the 
mid-axillary  line.  Its  fibres  pass  backwards,  closely  applied 
to  the  chest  wall,  and  are  inserted  into  the  ventral  aspect  of  the 
vertebral  border  of  the  scapula.  It  receives  its  nerve-supply 
from  the  long  thoracic  nerve  (of  Bell)  (C.  5,  6,  7)  (pp.  97,  131). 
The  serratus  anterior  pulls  the  scapula  forwards,  and,  when 
opposed  by  the  rhomboids,  it  steadies  the  scapula  in  the 
movements  of  forward  pushing.  In  addition,  by  rotating  the 
scapula  it  helps  to  produce  flexion  of  the  upper  arm  beyond  a 


32  THE  SUPERIOR  EXTREMITY 

right  angle   (p.   14),  and,  when  the  scapula  is  fixed  by  the 
trapezius  and  the  rhomboids,  it  acts  as  an  elevator  of  the  ribs. 

The  lateral  cutaneous  branches  of  the  second  and  third  intercostal 
nerves  pierce  the  medial  wall  and  run  laterally  across  the  axilla. 
They  supply  the  skin  over  the  floor  of  the  axilla  and  the  medial 
aspect  of  the  arm  ;  the  uppermost  is  termed  the  intercosto- 
brachial  (intercosto-humeral)  nerve,  and  it  communicates  with 
the  medial  cutaneous  nerve  of  the  arm  (lesser  internal  cutaneous). 
In  malignant  disease  of  the  breast  intermittent  pain  may  be 
referred  to  the  medial  side  of  the  arm,  in  the  area  supplied  by 
these  two  nerves.  It  is  suggested  that  this  is  due  to  pressure 
on  the  intercosto-brachial  nerve  by  enlarged  axillary  lymph 
glands  ;  but  the  pain  is  very  frequently  referred  from  the 
irritated  sympathetic  branches  supplying  the  mammary  gland 
itself. 

The  Lateral  Wall  of  the  Axilla,  to  which  the 
important  vessels  and  nerves  are  closely  related,  is  narrow  and 
is  formed  by  the  biceps,  the  coraco-brachialis,  and  the  proximal 
part  of  the  humeral  shaft. 

The  Axillary  Sheath  is  a  prolongation  of  the  prevertebral 
fascia  (p.  112)  from  the  neck.  It  encloses  the  vessels  and 
nerves  (and  some  of  the  apical  lymph  glands),  and  gradually 
becomes  lost  upon  them  as  they  pass  through  the  axilla.  In 
malignant  disease  of  the  breast,  the  apical  lymph  glands  are 
removed,  and  they  may  be  exposed  by  resecting  a  part  of  the 
sheath  and  separating  the  artery  from  the  vein. 

AXILLARY  ARTERY. — The  course  of  the  axillary  artery  may 
be  mapped  out  on  the  surface  by  drawing  a  line  from  the  middle 
of  the  clavicle  to  the  medial  side  of  the  elevation  formed  by  the 
coraco-brachialis  (p.  38),  the  limb  being  abducted  to  a  right 
angle.  The  vessel  is  about  six  inches  long  and  extends  from 
the  outer  border  of  the  first  rib  to  the  lower  border  of  the 
teres  major.  It  is  conveniently  divided  into  three  parts  by 
the  pectoralis  minor.  The  First  Part  lies  above  the  muscle  ; 
the  Second,  behind  the  muscle  ;  the  Third,  below  the  muscle. 

The  First  Part  of  the  axillary  artery  lies  behind  the 
costo-coracoid  membrane  and  the  clavicular  head  of  the  pectoralis 
major,  and  it  is  crossed  by  the  cephalic  and  thoraco-acromial 
veins.  Posteriorly,  the  artery  rests  on  the  first  intercostal  space 
and  the  first  digitation  of  the  serratus  anterior,  but  it  is  separated 
from  them  by  the  long  thoracic  nerve  (of  Bell),  and,  usually, 
the  medial  cord  of  the  brachial  plexus.  To  the  lateral  side  are 


THE  BREAST  AND  AXILLA  33 

the  lateral  and  posterior  cords  of  the  brachial  plexus ;  to  the 
medial  side,  and  overlapping  the  artery  anteriorly,  is  the  axillary 
vein. 

Ligature  of  this  part  of  the  artery  has  been  referred  to 
already  (p.  30).  The  collateral  circulation  is  carried  on  by  the 
scapular  anastomosis,  where  the  transverse  scapular  (supra- 
scapular)  (p.  14)  and  the  descending  branch  of  the  transverse 
cervical,  from  the  subclavian  (p.  12),  meet  the  subscapular  and 
circumflex  scapular  (dorsalis  scapulae)  branches  from  the 
axillary.  Further,  branches  from  the  intercostals  anastomose 
on  the  chest  wall  with  the  lateral  (long)  thoracic  and  subscapular 
arteries  and  with  the  pectoral  branches  of  the  thoraco-acromial. 

The  superior  thoracic  is  the  only  branch  of  the  first  part  of 
the  axillary  artery.  It  crosses  the  apex  of  the  axilla  to  supply 
the  lymph  glands  and  other  structures  in  the  first  intercostal 
space. 

The  Second  Part  of  the  axillary  artery  has  the  lateral 
cord  of  the  brachial  plexus  to  its  lateral  side,  the  posterior 
cord  behind  it,  and  the  medial  cord  and  the  medial  anterior 
thoracic  nerve,  which  separate  the  artery  from  the  axillary  vein, 
to  its  medial  side.  Behind  the  artery  and  the  posterior  cord 
there  is  a  pad  of  fat,  which  intervenes  between  them  and  the 
subscapularis  muscle. 

The  branches  of  this  part  of  the  artery  are  the  thoraco- 
acromial  (p.  30)  and  the  lateral  thoracic  (p.  31). 

The  Third  Part  of  the  axillary  artery  lies  under  cover 
of  the  pectoralis  major  above,  but  it  is  subcutaneous  below. 
There  are  two  nerves  on  each  side  of  the  artery.  Laterally,  lie 
the  lateral  head  of  the  median  and  the  musculo-cutaneous  nerve, 
which  deviates  laterally  to  pierce  the  coraco-brachialis  (Fig.  10). 
Anteriorly,  lie  the  medial  head  of  the  median  and  the  medial 
cutaneous  nerve  of  the  forearm  (internal  cutaneous  nerve). 
Medially,  the  ulnar  nerve  separates  the  artery  from  the  axillary 
vein,  and  the  medial  cutaneous  nerve  of  the  arm  (lesser  internal 
cutaneous  nerve)  is  closely  applied  to  the  medial  side  of  the 
vein.  Posteriorly  are  the  radial  (musculo-spiral)  and  axillary 
(circumflex)  nerves,  but  the  latter  leaves  the  artery  at  the 
lower  border  of  the  subscapularis  by  passing  backwards  into 
the  quadrilateral  space. 

The  Third  Part  of  the  axillary  artery  is  superficial,  and  is 
the  site  of  election  for  Ligation.  The  vessel  may  be  tied 
immediately  above  the  origin  of  the  subscapular  or  between 

3 


34  THE  SUPERIOR  EXTREMITY 

this  vessel  and  the  posterior  circumflex.  In  the  former  case, 
the  circulation  is  carried  on  by  the  anastomosis  between  the 
intercostals,  lateral  thoracic,  descending  branch  of  transverse 
cervical,  transverse  scapular  (supra-scapular),  and  thoraco- 
acromial  arteries,  on  the  proximal  side  of  the  ligature,  and  the 
subscapular  and  humeral  circumflex  arteries,  on  the  distal  side 
of  the  ligature. 

Collateral  Circulation.  —  The  circumflex  arteries  anastomose  with 
the  acromial  branch  of  the  thoraco-acromial  and  the  transverse  scapular 
(p.  1 8).  The  subscapular  anastomoses  with  the  descending  branch  of  the 
transverse  cervical  and  the  transverse  scapular  arteries  in  the  scapular 
anastomosis,  and  with  the  intercostals,  the  lateral  thoracic  and  pectoral 
branches  of  the  thoraco-acromial  in  the  serratus  anterior,  near  the  inferior 
angle  of  the  scapula. 

When  the  axillary  artery  is  tied  between  the  subscapular  and  circumflex 
vessels,  the  anastomosis  just  referred  to  between  the  circumflex,  the  acromial 
branch  of  the  thoraco-acromial  and  the  transverse  scapular  arteries  re- 
establishes the  circulation. 

When  the  subscapular  and  circumflex  vessels  arise  by  a  common  trunk 
and  a  ligature  is  applied  distal  to  this  vessel,  the  collateral  anastomosis  follows 
the  same  course  as  in  ligature  of  the  brachial  artery  proximal  to  the  origin 
of  the  (superior)  profunda  (p.  43). 

Branches  of  the  Third  Part  of  the  Axillary  Artery.— (i)  The 
subscapular  is  the  largest  branch  of  the  axillary  artery.  It  arises  near  the 
lower  border  of  the  subscapularis,  along  which  it  descends  accompanied 
by  its  companion  vein  and  the  thoraco-dorsal  (long  subscapular)  nerve. 
A  short  distance  from  its  origin  it  gives  off  the  circumflex  scapular  (dorsalis 
scapulce)  artery,  which  winds  round  the  axillary  border  of  the  scapula  close, 
to  the  bone  to  reach  its  dorsal  surface  (p.  33).  (2)  The  posterior  circumflex 
(p.  18).  (3)  The  anterior  circumflex  (p.  18). 

These  three  arteries  occasionally  arise  by  a  common  trunk,  which  leaves 
the  third  part  of  the  axillary  artery  near  its  commencement. 

Aneurism  of  the  first  part  of  the  axillary  artery  pushes  forwards  the  costo- 
coracoid  membrane  and  tends  to  project  below  the  clavicle  in  the  superficial 
infra-clavicular  triangle.  Aneurism  of  the  third  part  projects  into  the  axilla 
and  gives  rise  to  a  swelling  or  convexity  of  the  floor  of  the  axilla.  Both 
varieties  may  press  upon  the  axillary  vein  and  obstruct  the  venous  return, 
thus  causing  swelling  and  redema  of  the  upper  limb. 

The  Axillary  Vein  is  formed  at  the  lower  border  of  the 
teres  major  by  the  basilic  vein,  and  is  soon  joined  by  the  venae 
comites  of  the  brachial  artery.  It  ends  at  the  outer  border 
of  the  first  rib,  where  it  becomes  continuous  with  the  subclavian 
vein.  As  it  passes  through  the  axilla  it  lies  to  the  medial  side 
of  the  artery,  but  is  separated  from  it  by  the  ulnar  nerve,  below, 
and  by  the  medial  cord  of  the  plexus,  above.  When  the  arm  is 
abducted,  the  vein  lies  in  front  of  the  artery  and  hides  it  from 
view.  Its  principal  tributaries  are  the  cephalic  and  the 
subscapular  veins.  The  latter  possesses  a  wide  anastomosis 
with  the  veins  of  the  thoracic  wall  near  the  inferior  angle  of 


THE  BREAST  AND  AXILLA  35 

the  scapula.  The  subscapular  vein  and  the  branches  of  the 
anastomosis  are  associated  with  the  posterior  group  of  lymph 
glands,  and  all  these  structures  are  removed,  as  a  routine  measure, 
in  excision  of  the  breast.  After  the  thoraco-dorsal  (long 
subscapular)  nerve  has  been  isolated,  the  subscapular  vessels 
are  tied  close  to  the  axillary  artery  and  then  stripped  downwards. 
In  the  process  the  lower  (middle)  subscapular  nerve  is  exposed, 
as  it  runs  laterally,  in  front  of  the  subscapularis  and  behind  the 
vessels,  to  reach  the  teres  major. 

The  LYMPH  GLANDS  of  the  axilla  are  arranged  in  four  groups  : 

1.  The  Pectoral  lymph  glands  lie  in  the  medial  part  of 
the  interval  between  the  suspensory  ligament  of  the  axilla 
(p.  30)  and  the  posterior  surface  of  the  pectoralis  major.    They 
drain  not  only  the  breast,  but  also  the  superficial  layers  of  the 
anterior  abdominal  wall  above  the  umbilicus. 

An  abscess  arising  from  these  glands  cannot  extend  upwards 
into  the  neck  as  the  two  layers  of  fascia  between  which  it  lies 
are  both  attached  to  the  clavicle  (Fig.  9).  This  abscess  tends 
to  point  either  at  the  upper  or  lower  border  of  the  pectoralis 
major.  Incisions  should  be  made  parallel  to  these  borders  to 
avoid  injuring  the  deltoid  branch  of  the  thoraco-acromial  artery 
(p.  30)  in  the  one  case;  and  the  lateral  thoracic  artery  (p.  31) 
in  the  other. 

2.  The    Central    lymph    glands    (Leaf)    accompany    the 
axillary  vein  and  lie  on  the  lateral  wall  of  the  axilla.    They 
receive  the  efferents  from  the  upper  limb  and  are  involved  early 
in  lymphangitis  of  the  fingers  and  forearm. 

An  abscess  arising  from  these  glands  lies  in  the  axilla  behind 
the  clavi-pectoral  fascia  and  produces  a  bulging  of  the  axillary 
fascia.  The  pus  cannot  pass  far  backwards  owing  to  the 
attachment  of  the  serratus  anterior  to  the  scapula,  but  it  may 
burrow  through  the  intercostal  spaces  and  infect  the  pleura,  or 
it  may  pass  upwards  behind  the  axillary  sheath  (p.  32)  and 
appear  in  the  root  of  the  neck.  Rarely,  the  pus  burrows  through 
the  subscapularis  and  infects  the  shoulder-joint. 

This  abscess  should  be  opened  through  the  axillary  fascia 
by  cutting  in  the  direction  of  the  medial  wall  and  parallel  to  the 
long  thoracic  nerve  (of  Bell).  In  this  way  the  lateral  thoracic 
artery  on  the  anterior  wall,  the  subscapular  vessels  and  thoraco- 
dorsal  nerve  on  the  posterior  wall,  and  the  great  vessels  and 
nerves  on  the  lateral  wall,  are  all  avoided. 

3.  The   Subscapular  group  of  lymph  glands  lies  on  the 

3  a 


THE  SUPERIOR  EXTREMITY 


subscapularis  at  the  inferior  angle  of  the  scapula  and  is  closely 
associated  with  the  subscapular  vessels  and  the  thoraco-dorsal 
nerve.  They  receive  efferents  from  the  pectoral  plexus  and 
afferents  from  the  superficial  layers  of  the  back  corresponding 
to  the  thoracic  part  of  the  vertebral  column. 


Pectoralis  major,  clavicular  part 


Cephalic  vein 
Clavicle 

Pectoral  branches  of thoraco- 

acromial  artery 

Pectoralis  minor,  partially 

reflected 

Infra -clavicular  lymph  glands 

Apical  lymph  glands  _MS^. 


Central  lymph 
glands 

Thoraco-dorsal 
|3C.  r  •        nerve 
f    i  7"  Subscapular  vein 

~3'i^S^~Tf-4  .Long  thoracic  nerve 

~~^T  -  Subscapular  lymph  glani 
-gpJ  Latissimus  dorsi 
Serratus  anterior 


Pectoralis 
major,  pars 
abdominalis 


External  oblique 


FIG.  10. — The  Axilla  and  its  Lymph  Glands.  A  small  part  of  the  anterior 
wall  of  the  rectus  sheath  has  been  removed,  and  the  pectoralis  minor 
has  been  partially  divided. 

Abscesses  arising  in  connection  with  this  group  may  spread 
in  the  same  directions  as  in  (2).  They  should  be  opened  by  an 
incision  parallel  to  the  axillary  border  of  the  scapula,  so  as 
to  avoid  injury  to  the  subscapular  vessels  and  nerve. 

4.  The  Apical  lymph  glands  are  situated  at  the  apex  of 
the  axilla  and  lie  behind  the  costo-coracoid  membrane.  Some 


THE  BREAST  AND  AXILLA  37 

lie  on  the  first  intercostal  space ;  others  along  the  axillary 
sheath ;  while  others  are  situated  within  the  sheath  in  contact 
with  the  vein.  They  receive  the  efferents  of  the  subscapular, 
pectoral,  and  central  groups,  and  are  connected,  through  the 
costo-coracoid  membrane,  with  the  infra -clavicular  lymph 
glands  in  the  superficial  infra-clavicular  triangle.  The  apical 
lymph  glands  may  become  adherent  to  the  axillary  vein  in 
malignant  disease  and  necessitate  the  excision  of  a  part  of  that 
vessel ;  they  may  also  press  upon  the  cephalic  vein,  as  it  pierces 
the  costo-coracoid  membrane  in  such  a  way  as  to  render  it 
prominent  throughout  its  course, in  the  arm.  Efferents  from 
this  group  open  into  the  lymph  glands  at  the  root  of  the  neck, 
and  Halstead  considers  that  these  should  be  removed  in  the 
routine  operation  for  scirrhus  mammae. 

The  Posterior  Wall  of  the  Axilla  is  formed  by  the  subscapularis, 
teres  major,  and  the  tendon  of  the  latissimus  dorsi. 

The  Subscapularis  arises  from  the  venter  of  the  scapula  and  passes  upwards 
and  laterally  in  front  of  the  shoulder -joint  to  be  inserted  into  the  lesser 
tubercle  of  the  humerus  and  the  capsule  of  the  joint.  It  helps  in  adduction 
and  medial  rotation  of  the  arm  and  receives  its  nerve-supply  from  the  upper 
(short)  and  lower  (middle)  subscapular  nerves  (C.  5  and  6). 

The  Latissimus  dorsi  (p.  269)  is  inserted  into  the  floor  of  the  intertubercular 
sulcus  of  the  humerus.  It  helps  in  extension,  adduction,  and  medial  rotation 
of  the  arm  and  is  supplied  by  the  thoraco-dorsal  (long  subscapular)  nerve 
(C.  6,  7,  and  8). 

The  Teres  major  arises  from  the  dorsal  aspect  of  the  inferior  angle  of  the 
scapula  and  runs  upwards  and  laterally  to  be  inserted  into  the  medial  lip 
of  the  intertubercular  sulcus.  Its  course  corresponds  to  that  of  the  latissimus 
dorsi  and  its  actions  are  therefore  similar.  It  is  supplied  by  the  lower  (middle) 
subscapular  nerve  (C.  5  and  6). 

The  great  vessels  and  nerves  of  the  axilla  lie  on  the  upper  part  of  this 
wall,  and  the  subscapular  vessels  (p.  34)  and  the  three  subscapular  nerves, 
which  all  arise  from  the  posterior  cord,  are  closely  related  to  it. 

The  BRACHIAL  PLEXUS  and  its  important  branches  will  be 
considered  in  detail  in  a  subsequent  chapter  (p.  95),  but  the 
nerves  must  be  identified  as  they  surround  the  third  part  of  the 
axillary  artery.  The  Median  is  recognised  by  its  two  heads 
of  origin  and  by  its  great  size.  The  Musculo  -  Cutaneous  is 
recognised  by  its  lateral  position  and  by  its  deviation  to  reach 
and  pierce  the  coraco-brachialis.  It  is  smaller  than  the  median, 
but  occasionally  it  includes  a  large  part  of  the  lateral  head  of 
the  median,  and  the  two  nerves  then  tend  to  resemble  one 
another  and  can  be  distinguished  only  by  their  relative  positions. 
This  part  of  the  lateral  head  subsequently  joins  the  median 
nerve  in  the  arm. 

Some  difficulty  may  be  experienced  in  distinguishing  the 

36 


38  THE  SUPERIOR  EXTREMITY 

Ulnar  from  the  Medial  Cutaneous  Nerve  of  the  Forearm 
(Internal  Cutaneous).  They  both  arise  from  the  medial  cord 
and  are  hidden  at  their  origin  by  the  axillary  vein.  The  medial 
cutaneous  is  the  more  anterior  and  the  smaller  of  the  two. 

The  Radial  (Musculo-spiral)  is  the  direct  continuation  of 
the  posterior  cord  and  consequently  lies  behind  the  artery. 
It  can  be  distinguished  from  the  ulnar  by  its  greater  size  and 
by  its  position. 


REGION  OF'(UPPER)  ARM. 

Muscular  Landmarks. — The  elevation  produced  by  the 
biceps  on  the  front  of  the  arm  is  limited  by  the  lateral  and 
medial  bicipital  furrows.  In  its  proximal  part  the  medial  furrow 
is  obscured  by  the  coraco-brachialis }  which  is  seen  best  when 
resistance  is  offered  to  adduction  of  the  abducted  arm. 

When  the  elbow  is  forcibly  extended  against  resistance,  the 
lateral  head  of  the  triceps  gives  rise  to  a  distinct  prominence, 
which  lies  below  and  parallel  to  the  posterior  border  of  the 
deltoid.  The  long  head  of  the  triceps  can  be  seen,  as  it  emerges 
from  under  cover  of  the  proximal  part  of  the  posterior  border 
of  the  deltoid,  when  the  abducted  arm  is  viewed  from  behind. 
The  muscular  mass  on  the  medial  aspect  of  the  back  of  the 
arm  is  produced  by  the  large  medial  head  of  the  triceps. 

The  Deep  Fascia  of  the  Arm  receives  attachments  to  the 
humeral  epicondyles  and  the  subcutaneous  border  of  the 
olecranon  in  the  elbow  region.  The  Medial  and  Lateral 
Intermuscular  Septa  are  processes  of  fascia  which  extend  from 
the  ensheathing  layer  to  the  epicondylic  ridges  and  shaft  of  the 
humerus.  The  medial  septum  extends  from  the  medial 
epicondyle  to  the  insertion  of  the  coraco-brachialis,  the  lateral 
from  the  lateral  epicondyle  to  the  insertion  of  the  deltoid.  These 
septa,  together  with  the  humerus,  divide  the  arm  into  an  anterior 
and  a  posterior  compartment,  and,  to  a  certain  extent,  limit 
the  course  of  pus  or  hsemorrhagic  extravasation. 

The  Triceps  Brachii  occupies  the  whole  of  the  posterior 
compartment  of  the  arm,  and  is  inserted  into  the  proximal 
surface  of  the  olecranon.  It  is  a  powerful  extensor  of  the  elbow, 
and  it  is  supplied  by  the  radial  (musculo  -  spiral)  nerve  (C.  7 
and  8). 


REGION  OF  (UPPER)  ARM  39 

The  Axillary  (Circumflex)  Nerve  (p.  33)  winds  horizontally 
round  the  surgical  neck  of  the  humerus  in  the  quadrilateral 
space,  where  it  is  in  close  relation  to  the  dependent  part  of  the 
capsule  of  the  shoulder- joint  (p.  16).  In  this  region  it  may  be 
injured  by  the  pressure  of  a  crutch,  by  the  head  of  the  humerus 
in  sub-glenoid  dislocations,  and  by  the  fragments  in  fracture  of 
the  surgical  neck.  The  nerve  supplies  the  teres  minor  and  the 
deltoid.  It  can  be  mapped  out  on  the  surface  by  a  horizontal 
line,  which  intersects  the  line  drawn  from  the  lateral  border  of 
the  acromion  to  the  insertion  of  the  deltoid,  at  the  junction  of 
its  proximal  and  middle  thirds.  The  results  of  injury  to  the 
axillary  nerve  are  described  on  page  101. 

Surgical  Approach  to  the  Proximal  Part  of  the 
Humerus. — In  disease  or  injury  of  the  Proximal  Part  of  the 
Shaft  (or  diaphysis)  of  the  humerus,  the  best  approach  is 
obtained  by  a  long  incision,  parallel  to  the  posterior  border  of 
the  deltoid  (Stiles).  When  the  muscle  is  undermined  and 
retracted,  the  quadrilateral  space  is  exposed,  and  the  large 
cutaneous  branch  of  the  axillary  nerve  is  seen  passing  forwards 
round  the  edge  of  the  deltoid.  The  quadrilateral  space  is  bounded 
above  by  the  teres  minor,  below  by  the  teres  major,  laterally 
by  the  surgical  neck  of  the  humerus,  and  medially  by  the  long 
head  of  the  triceps.  Through  it  the  axillary  nerve  and  the 
posterior  circumflex  vessels  pass  backwards  in  close  relation  to 
the  surgical  neck  of  the  humerus  and  the  dependent  part  of  the 
capsule  of  the  shoulder -joint.  Anterior  to  the  origin  of  the 
lateral  head  of  the  triceps  and  above  the  insertion  of  the  deltoid, 
the  humerus  is  uncovered  by  muscles  and  offers  good  access  to 
the  surgeon. 

The  proximal  part  of  the  diaphysis  of  the  humerus  may 
be  resected  subperiosteally  for  tuberculous  osteomyelitis.  After 
the  periosteum  has  been  elevated,  the  diaphysis  need  only  be 
divided  distal  to  the  disease,  as  the  part  to  be  resected  may 
then  be  wrenched  out  from  its  periosteal  sheath.  In  this  way 
the  epiphyseal  cartilage  is  left  attached  to  the  epiphysis  and 
the  joint  cavity  is  not  opened  (Fig.  6). 

Below  the  teres  major  the  Radial  (musculo  -  spiral)  nerve 
lies  on  the  long  head  of  the  triceps,  and  after  supplying  this 
muscle,  it  enters  the  radial  groove  in  company  with  the  (superior) 
profunda  branch  of  the  brachial  artery.  In  the  groove  it  supplies 
the  medial  and  lateral  heads  of  the  triceps  between  which  it 
lies,  and  it  passes  distally  and  laterally  across  the  back  of  the 

3c 


40        THE  SUPERIOR  EXTREMITY 

arm.  At  the  distal  end  of  the  groove  it  pierces  the  lateral 
intermuscular  septum  and  enters  the  anterior  compartment 
of  the  arm.  The  point  at  which  it  pierces  the  septum  may  be 
indicated  on  the  surface  at  the  union  of  the  proximal  and  middle 


Spine  of  scapula        N.  suprascapularis 

j      A    M.  dehoid.us 


M.  infraspinatus 
A.  circumflex,  scap. 

(O.T.  dorsalis  I. -^ 

scap.) 
M.  teres  minor  J 

M.  subscapularisJ 


M.  teres  major 

Triang.  space     . 
Quadrangular  space 

M.  triceps  cap.  long 
N.  radialis  (O.T.  musculo-spiral) 


Bursa  subacromialis 

M.  infraspinatus 
_  Capsula  artic.  Articulat. 
humeri ; 
N.  to  m.  teres  minor 

M.  deltoideus 

N.  axillaris  (O.T. 
circumflex) ram.  sup. 
N.  axillaris, 
ram.  inf. 


N.  cutan.  brach. 
~  lat. 


-   M.  triceps,  cap.  lat. 


A.  brachialis 
M.  triceps,  cap.  lat. 

N.  to  m.  triceps,  cap.  nied. 


M.  triceps,  cap.  med. 


N.  ulnaris 

Epicond.  med 

N.  flex.  carp.  uln. 

Olecranon— --. 


N.  radialis  (O.T. 
musculo-spiral) 


A.  prof,  brachii  ram.  ant. 

A.  prof  brachii  ram.  post. 
N.  cut.  antib.  dorsalis 
M.  brachialis 


Epicond.  lat. 

A.  inteross.  recurr. 


M.  anconaeus 
Mm.  ext.  dig. 
comm.  et  dig.  quint. 
M.  ext.  carp,  ulnaris 


FIG.    ii. — The  Back  of  the  Arm. 


thirds  of  the  line  joining  the  lateral  epicondyle  to  the  insertion 
of  the  deltoid.  A  line  drawn  across  the  back  of  the  arm  from 
the  termination  of  the  axillary  artery  to  this  point  maps  out 
the  nerve  as  it  lies  in  the  radial  groove. 

In  the  anterior  compartment  the  radial   (musculo-spiral) 


REGION  OF  (UPPER)  ARM  41 

nerve  lies  on  the  lateral  border  of  the  brachialis  (b.  anticus), 
and  is  covered  in  front  by  the  brachio-radialis  (supinator  longus) 
proximally  and  the  extensor  carpi  radialis  longus  distally.  It 
ends  in  front  of  the  lateral  epicondyle  of  the  humerus  by  dividing 
into  superficial  (radial)  and  deep  (posterior  interosseous)  branches. 
Callus  following  a  fracture  of  the  shaft  of  the  humerus 
sometimes  implicates  the  radial  (musculo  -  spiral)  nerve, 
necessitating  operative  interference.  The  nerve  can  be 
conveniently  found  as  it  pierces  the  lateral  intermuscular 
septum,  and  it  can  then  be  traced  upwards  by  cutting  through 
the  musculo  -  tendinous  roof  of  the  radial  groove,  until  the 
damaged  portion  is  found.  In  the  usual  procedure  the  nerve 
is  sought  for  in  the  anterior  compartment  by  separating  the 
brachio-radialis  from  the  brachialis  (b.  anticus).  Owing  to  the 
absence  of  a  well-marked  septum,  the  groove  between  these 
muscles,  which  are  closely  applied  to  one  another,  is  not  easy 
to  determine.  The  interval  between  the  brachialis  and  the 
biceps  may  inadvertently  be  opened,  in  which  case  the  musculo- 
cutaneous  nerve  is  exposed  (vide  infra).  Injury  to  the  radial 
(musculo-spiral)  nerve  is  dealt  with  on  p.  101. 

Muscles  of  the  anterior  compartment.  —  The  coraco  -  brachialis 
is  inserted  into  the  middle  of  the  shaft  of  the  humerus  on  the  medial  side, 
and  helps  in  flexion  and  adduction  of  the  arm.  Its  nerve -supply  from 
the  musculo-cutaneous  nerve  is  derived  entirely  from  C.  7. 

The  biceps  brachii  arises  by  a  long  head  (p.  18)  and  by  a  short  head  from 
the  tip  of  the  coracoid  process.  It  is  inserted  into  the  posterior  part  of  the 
tuberosity  of  the  radius  and  is  separated  from  the  anterior  part  by  a  bursa. 
Primarily,  it  is  a  flexor  and  supinator  of  the  forearm  ;  secondarily,  it  helps 
to  produce  flexion  and  adduction  at  the  shoulder.  The  musculo-cutaneous 
nerve  (C.  5  and  6)  supplies  both  heads. 

The  biceps  occupies  the  greater  part  of  the  anterior  compartment  of  the 
arm,  and  its  medial  border  is  the  surgical  guide  to  the  brachial  artery.  The 
belly  or  either  head  of  the  muscle  may  be  ruptured  during  violent  movements, 
and,  as  a  result,  flexion  of  the  elbow  and  forcible  supination  are  much 
weakened. 

The  brachialis  (b.  anticus)  covers  the  distal  half  of  the  anterior  surface 
of  the  humerus  and  passes  in  front  of  the  anterior  ligament  of  the  elbow  to 
be  inserted  into  the  front  of  the  coronoid  process  of  the  ulna.  It  is  a  powerful 
flexor  of  the  elbow,  and  it  derives  its  nerve-supply  from  the  musculo-cutaneous 
(C.  5  and  6)  and  the  radial  (musculo-spiral)  nerves  (C.  5  and  6). 

In  fracture  of  the  distal  part  of  the  shaft  of  the  humerus  a  portion  of 
the  brachialis  may  become  interposed  between  the  two  fragments  causing 
non-union. 

The  shaft  of  the  humerus  should  be  examined  along  the 
lines  of  the  intermuscular  septa  (p.  38),  as  the  anterior  and 
posterior  surfaces  of  the  bone  are  obscured  by  muscles.  At 
its  distal  end,  however,  it  may  be  examined  by  deep  pressure 


42  THE  SUPERIOR  EXTREMITY 

through  the  brachialis  in  front  and  the  triceps  behind,  provided 
that  the  muscles  are  relaxed  by  supporting  the  elbow. 

Fractures  of  the  Humerus.— Some  reference  must  be 
made  to  the  common  sites  of  fracture  of  the  humeral  shaft  on 
account  of  the  displacement  of  the  fragments.  Although  the 
displacements  may  be  due  primarily  to  the  direction  of  the 
force  causing  the  fracture,  ultimately  they  are  due  to  the  action 
of  the  muscles  attached  to  the  fragments. 

Fractures  may  occur : 

1.  Through  the  Anatomical  Neck  (p.  23). 

2.  Through  the   Surgical   Neck. — The  proximal  fragment 
is  slightly  abducted  by  the  supra-spinatus,  but  is  not  rotated, 
as  the  lateral  rotators  attached  to  the  greater  tubercle  are 
opposed   by   the   subscapularis   on  the   lesser  tubercle.    The 
distal  fragment  is  drawn  proximally  by  the  triceps,  the  biceps, 
and  the  deltoid,  and  medially  by  the  muscles  inserted  into  the 
intertubercular  sulcus  (bicipital  groove). 

3.  Immediately  Proximal  to  the  Insertion  of  the  Deltoid. 
—The    proximal    fragment    is    adducted    by   the    latissimus 
dorsi,  the  pectoralis  major,  and  the  teres  major.    The  distal 
fragment  is  drawn  proximally  by  the  deltoid,  the  triceps,  and 
the  biceps. 

4.  Distal  to  the  Insertion  of  the  Deltoid. — The  proximal 
fragment  tends  to  be  abducted  by  the  deltoid.    The  distal 
fragment  is  drawn  proximally  and  somewhat  medially  by  the 
biceps  and  the  triceps,  which  act  through  the  elbow-joint. 

5.  Proximal    to   the    Epicondyles    (p.   63).  —  The   distal 
fragment  is  usually  drawn  proximally  behind  the  proximal 
fragment  by  the  biceps  and  the  triceps.    The  distal  end  of  the 
proximal  fragment  may  perforate  the  brachialis  and  injure  the 
brachial  artery. 

The  Musculo-cutaneous  nerve,  on  leaving  the  axillary 
artery  (p.  33),  supplies  the  coraco-brachialis  and  then  pierces  it. 
It  runs  distally  between  the  biceps  in  front  and  the  brachialis 
behind,  supplying  both  muscles,  and  emerges  at  the  elbow  at 
the  lateral  side  of  the  tendon  of  the  biceps  (p.  47).  The  results 
of  injury  to  this  nerve  are  detailed  on  p.  102. 

The  Brachial  Artery  is  the  direct  continuation  of  the 
axillary.  It  begins  at  the  lower  border  of  the  teres  major  and 
ends  in  the  cubital  fossa  (p.  45),  half  an  inch  distal  to  the 
mid -point  of  the  line  joining  the  two  epicondyles,  where  it 
divides  into  the  radial  and  ulnar  arteries. 


REGION  OF  (UPPER)  ARM  43 

In  its  proximal  third  the  artery  lies  to  the  medial  side  of 
the  humerus  and  can  be  compressed  laterally  against  the  bone. 
In  ligature  of  this  part  the  artery  is  found  immediately  under 
the  deep  fascia,  but  it  is  overlapped  laterally  by  the  coraco- 
brachialis,  from  which  it  is  partially  separated  by  the  median 
nerve.  Both  the  medial  cutaneous  nerve  of  the  forearm  (internal 
cutaneous)  and  the  ulnar  nerve  (p.  38)  lie  to  its  medial  side 
and  separate  it  from  the  basilic  vein.  Behind  the  artery  lie 
the  long  head  of  the  triceps  and  the  radial  (musculo-spiral)  nerve. 

The  middle  third  of  the  brachial  artery  can  be  compressed 
backwards  and  laterally  against  the  bone.  In  ligation  of 
this  part  the  artery  is  found  to  be  overlapped  by  the  medial 
border  of  the  biceps,  and  to  be  covered  by  the  median 
nerve,  which  crosses  it  very  obliquely  about  the  middle  of  the 
arm.  The  ulnar  nerve  lies  to  its  medial  side,  but  is  diverging 
from  the  artery  to  reach  the  medial  intermuscular  septum. 
Posteriorly,  it  lies  on  the  insertion  of  the  coraco-brachialis  and 
on  the  brachialis.  The  medial  cutaneous  nerve  of  the  forearm 
(internal  cutaneous)  and  the  basilic  vein  are  both  separated 
from  the  vessel  by  the  deep  fascia,  which  they  pierce  at  the 
middle  of  the  arm. 

The  distal  third  of  the  artery  lies  in  front  of  the  distal 
part  of  the  humerus  and  can  be  compressed  backwards  against 
it.  In  ligature  of  this  part,  the  artery  is  found  to  be  overlapped 
by  the  medial  border  of  the  biceps,  but  near  its  termination  it 
lies  to  the  medial  side  of  the  tendon  of  that  muscle  and  is  crossed 
anteriorly  by  the  lacertus  fibrosus  (bicipital  fascia)  (p.  45). 
The  median  nerve  lies  to  its  medial  side. 

Branches. — (i)  The  (Superior)  Pro/undo,  arises  near  the  commencement 
of  the  brachial  artery  and  runs  with  the  radial  (musculo-spiral)  nerve. 

(2)  The  Superior  Ulnar  Collateral  (Inferior  Profunda)  usually  arises  near 
the  middle  of  the  arm  (p.  44). 

(3)  The  Inferior  Ulnar  Collateral  (Anastomolica  Magnd)  (p.  44). 

(4)  The  Nutrient  artery  usually  arises  from  a  muscular  branch  to  the 
brachialis  ;  it  may  be  injured  in  fractures  of  the  humerus,  and,  in  these  cases, 
it  is  said  that  delayed  union  results. 

Collateral  Anastomosis  —  (a)  Ligature  Proximal  to  the  Origin  of  the 
Profunda  Artery. — The  circulation  is  re-established  through  an  anastomosis 
which  occurs  between  a  descending  branch  from  the  posterior  circumflex 
(p.  1 8)  and  an  ascending  branch  from  the  profunda. 

(V)  Ligature  between  the  Origins  of  the  Profunda  and  the  Superior  Ulnar 
Collateral  (Inferior  Profunda). — The  profunda  artery  divides  into  anterior 
and  posterior  branches  at  the  distal  end  of  the  radial  (musculo-spiral)  groove. 
The  anterior  branch  accompanies  the  radial  (musculo-spiral)  nerve  into  the 
groove  between  the  brachio-radialis  and  the  brachialis  to  anastomose  with 
the  radial  recurrent,  which  enters  the  same  groove  at  its  distal  end.  The 


44  THE  SUPERIOR  EXTREMITY 

posterior  branch  runs  distally  behind  the  lateral  intermuscular  septum  and 
anastomoses  behind  the  lateral  epicondyle  with  the  dorsal  interosseous 
recurrent  (p.  71),  which  ascends  under  cover  of  the  anconseus,  upon  the 
supinator  (s.  brevis)  and  the  annular  (orbicular)  ligament.  It  is  also  joined 
by  a  transverse  branch  from  the  inferior  ulnar  collateral  (anastomotic)  artery. 

(c)  Ligature  between  the  Origins  of  the  Superior  and  Inferior  Ulnar  Collateral 
Arteries  (Inferior  Profunda  and  Anastomotic). — The  Superior  Ulnar  Collateral 
accompanies  the  ulnar  nerve  (p.  43).    The  Inferior  Ulnar  Collateral  arises 
two  inches  proximal  to  the  bend  of  the  elbow  and  runs  medially  upon  the 
brachialis,  passing  behind  the  median  nerve.     It  gives  off  an  anterior  branch, 
which  runs  distally  in  the  groove  between  the  brachialis  and  the  pronator 
teres  to  anastomose  with  the  anterior  ulnar  recurrent.    The  artery  then 
pierces  the  medial  intermuscular  septum  and  joins  the  superior  ulnar  collateral 
to  anastomose,  behind  the  medial  epicondyle,  with  the  posterior  ulnar  re- 
current. 

The  anastomosis  detailed  in  (b)  will  also  help  to  re-establish  the  circulation. 

(d)  Ligature  just  above  the   Termination  of  the  Brachial  Artery. — The 
collateral  circulation  is  the  same  as  that  described  in  (c). 

The  Medial  Supracondylar  Triangle  is  bounded  laterally 
by  the  brachial  artery  and  medially  by  the  medial  intermuscular 
septum.  Its  base  is  formed  by  the  medial  part  of  the  inter- 
condylar  line.  The  triangle  contains  the  median  nerve  and 
the  epitrochlear  lymph  gland,  the  former  behind  the  deep  fascia,, 
and  the  latter  superficial  to  it.  This  gland  is  very  often  the 
seat  of  lymphadenitis  and  abscess  formation,,  secondary  to 
septic  infection  of  the  fingers  or  forearm.  In  excision  of  the 
gland  the  volar  branch  of  the  medial  cutaneous  nerve  of  the 
forearm  (internal  cutaneous  nerve)  may  be  injured  (p.  48). 


THE  REGION  OF  THE  ELBOW. 

Bony  Landmarks. — Both  Epicondyles  of  the  Humerns  are 
subcutaneous  and  are  easily  recognised ;  the  medial  is  the 
more  prominent,  while  the  lateral  can  readily  be  traced  upwards 
into  the  lateral  epicondylic  ridge.  The  medial  epicondyle  is 
the  more  posterior,  since,  when  the  arm  is  at  rest  by  the  side, 
the  humerus  is  medially  rotated.  The  line  joining  the  two 
epicondyles  is  horizontal,  and,  in  complete  extension  of  the 
elbow,  it  passes  through  the  proximal  border  of  the  Olecranon, 
which  also  is  subcutaneous  As  the  elbow  is  flexed,  the  olecranon 
descends,  till  in  full  flexion  it  lies  at  least  an  inch  distal  to  the 
epicondyles.  Between  the  dorsal  surface  of  the  olecranon  and 
the  overlying  skin  there  is  a  bursa,  which  is  frequently  infected, 


THE  REGION  OF  THE  ELBOW        45 

through  abrasions  of  the  skin,  after  falls  on  the  elbow.  This 
may  cause  cellulitis  in  the  forearm  from  direct  spread.  Chronic 
inflammation  of  this  bursa  is  not  uncommon  in  miners. 

The  Head  of  the  Radius  can  be  felt  on  the  posterior  aspect 
of  the  limb.  When  the  forearm  is  flexed,  it  lies  nearly  an  inch 
in  front  of  the  lateral  epicondyle,  the  interval  between  the  two 
being  occupied  by  the  capitulum  (capitellum)  of  the  humerus. 
When  the  forearm  is  fully  extended,  the  tip  of  the  finger  may 
be  inserted  into  a  distinct  hollow  immediately  proximal  to  the 
head  and  behind  the  radial  collateral  (external)  ligament.  This 
hollow  corresponds  to  the  lateral  and  posterior  part  of  the 
radio  -  humeral  joint,  and  immediately  proximal  to  it  the 
subcutaneous  posterior  aspect  of  the  lateral  epicondyle  can  be 
made  out.  If  the  elbow  is  grasped  by  the  hand  so  that  the 
olecranon  fits  into  the  palm,  while  the  thumb  rests  over  the 
head  of  the  radius,  the  latter  will  be  felt  to  rotate  when  the 
forearm  is  alternately  pronated  and  supinated. 

Muscular  Landmarks. — The  flexor  muscles  on  the  medial 
side,  and  the  extensor  and  supinator  muscles  on  the  lateral  side, 
bound  the  cubital  fossa,  a  triangular  depression  in  front  of  the 
elbow,  distal  to  the  intercondylar  line.  Entering  the  fossa  is 
the  strong  tendon  of  the  biceps,  and  the  examining  finger  can 
readily  slip  into  the  depression  between  this  tendon  and  the 
brachio-radialis.  From  the  medial  border  of  the  tendon  the 
lacertus  fibrosus  (bicipital  fascia)  passes  distally  and  medially 
to  blend  with  the  fascia  covering  the  flexor  muscles.  It  hinders 
the  examination  of  the  depression  between  the  biceps  tendon 
and  the  flexor  muscles,  but  if  the  finger  is  inserted  behind  its 
prominent  proximal  border,  the  pulsations  of  the  brachial  artery 
can  readily  be  felt. 

Superficial  Nerves  of  the  Arm,  Elbow  Eegion,  and 
Forearm. — The  proximal  part  of  the  lateral  aspect  of  the  arm 
is  supplied  by  the  Axillary  (Circumflex)  Nerve  (C.  5  and  6).  Be- 
tween this  area  and  the  lateral  epicondyle  the  skin  is  supplied 
by  the  proximal  division  of  the  Dorsal  Cutaneous  Nerve  of  the 
Forearm  (Upper  External  Cutaneous  Branch  of  Musculo-SpiraJ) 
(C.  5  and  6),  which  arises  just  before  the  radial  (musculo-spiral) 
nerve  penetrates  the  lateral  intermuscular  septum.  It  at  once 
pierces  the  deep  fascia  and  associates  itself  with  the  cephalic 
vein.  The  Distal  Division  of  the  Dorsal  Cutaneous  Nerve  of  the 
Forearm  (Lower  External  Cutaneous  Branch  of  Musculo-SpiraT) 
(C.  6  and  7),  arises  just  distal  to  the  last-named,  runs  distally 


46 


THE  SUPERIOR  EXTREMITY 


behind  the  lateral  epicondyle  and  supplies  the  skin  on  the  back 
of  the  forearm  as  far  as  the  wrist  (Fig.  13). 


Posterior  supraclavicular  nerve* 


Lateral  cutaneous  nerve  of  the  arm 

Posterior  cutaneous  nerve  of  the  arm 

Intercosto-brachiat  nerve    - 

Branch  of  medial  cutaneous  nerve  of 

forearm 

Medial  cutaneous  nerve  of  the  arm 

Dorsal  cutaneous  nerve  of  forearm,  \ 
proximal  and  distal  branches  / 

Medial  cutaneous  nerve  of  forearm 

Cephalic  vein 

Basilic  vein 

Median  basilic  vein 

Median  cephalic  vein 

Lateral  cutaneous  nerve  of  forearm 

Profunda  vein 
Cephalic  vein 

Basilic  veins -j 
Median  vein 


Palmar  cutaneous  branch  of  median  nerve 
Palmar  cutaneous  branch  of  ulnar  nerve 

Palmar  cutaneous  branch  of  superficial 
branch  of  radial  nerve 


FIG.  12. — The  Superficial  Nerves  and  Veins  on  the  Front  of  the  Upper  Limb. 

The  lateral  aspect  of  the  forearm  is  supplied  by  the  Lateral 
Cutaneous  Nerve,  which  is  the  terminal  part  of  the  Musculo- 


THE  REGION  OF  THE  ELBOW        47 

Cutaneous  Nerve  (C.  5  and  6).     After  it  pierces  the  deep  fascia 

Posterior  supraclavicular  nerves 


Lateral  cutaneous  nerve  of  arm 

(  Posterior  cutaneous  nerve  of 

\  arm 

/  Dorsal  cutaneous  nerve  of 

\forearm,  proximal  branch 

Intercosto-brachial  nerve 


Medial  cutaneous  nerve  of  arm 
Dorsal  cutaneous  nerve  of  fore- 
arm, distal  branch 


Medial  cutaneous  nerve  of  forearm, 

ulnar  branch 


Lateral  cutaneous  nerve  of  forearm, 
dorsal  branch 


—Superficial  division  of  radial 
Dorsal  branch  of  ulnar  nerve 


FIG.  13. — The  Superficial  Nerves  on  the  Dorsal  Aspect  of  the  Upper  Limb. 

(p.  42),  it  crosses  the  median  cephalic  vein  and  divides  into 
volar  (anterior)  and  dorsal  branches. 

The  former  supplies  the  front  of  the  forearm  as  far  as  the 


THE  SUPERIOR  EXTREMITY 


thenar  eminence  ;   the  latter  winds  over  the  brachio-radialis  to 

supply  the  posterior  surface 
of  the  forearm  as  far  as  the 
wrist.  It  lies  lateral  to  the 
dorsal  cutaneous  nerve  of  the 
forearm  (lower  external  cut- 
aneous branch  of  musculo- 
spiral). 

The  medial  aspect  of  the 
arm  is  supplied  above  by  the 
Inter  co  sto-brachial  Nerve  (T.2), 
(p.  32),  and,  more  posteriorly,, 
by  the  Dorsal  Cutaneous  Nerve 
of  the  Arm  (C.  8)  (Internal 
Cutaneous  Branch  of  Musculo- 
spiral),  which  arises  before  the 
radial  nerve  enters  its  groove 
on  the  back  of  the  humerus. 

Distal  to  this  area  the  skin 
is  supplied  by  the  Medial 
Cutaneous  Nerve  of  the  Arm 
(Lesser  Internal  Cutaneous 
Nerve)  (T.  i  and  2),  as  far  as 
the  medial  epicondyle.  The 
skin  covering  the  biceps  is 
supplied  by  the  Medial  Cut- 
aneous Nerve  of  the  Forearm 
(Internal  Cutaneous  Nerve)  (C. 
8  and  T.  i),  which  pierces  the 
deep  fascia  at  the  insertion  of 
the  coraco-brachialis  and  ac- 
companies the  basilic  vein. 
Just  proximal  to  the  medial 
epicondyle  it  divides  into  volar 
(anterior)  and  ulnar  (posterior) 
FIG.  14.— Schematic  Representation  of  branches  which  Supply  the 
the  Distribution  of  the  Spinal  Nerves  medial  half  of  the  forearm  as 
to  the  Skin  on  the  Anterior  Aspect  ,  ^,  •  , 

of  the  Upper  Limb.  far  as  the  WTlst' 

It  will   be  observed  that 

V.A.L,  Ventral  axial  line. 

the  skin  on  the  lateral  aspect 

of  the  limb  is  supplied  by  the  upper  nerves  of  the  brachial 
plexus,  and  that  on  the  medial  side  by  the  lower.     The  innerva- 


THE  REGION  OF  THE  ELBOW 


49 


tion  of  the  limb  at  an  early  stage  of  development  provides  a 
useful  explanation. 
At  the  fourth  week 
of  embryonic  life 
the  upper  limb  pro- 
jects from  the  side 
of  the  neck  region 
as  a  small  bud, 
which  possesses  a 
ventral  and  a  dor- 
sal surface,  a  ceph- 
alic (pre-axial)  and 
a  caudal  (post- 
axial)  border.  The 
anterior  rami  (ant- 
erior primary  divi- 
sions) of  the  lower 
four  cervical  and 
the  first  thoracic 
nerves  grow  out 
into  the  bud  ;  C.  5 
supplies  the  pre- 
axial  border,  and 
T.  i  the  post-axial. 
As  the  limb  length- 
ens, C.  6  and  C.  8 
reach  the  respec- 
tive borders  of  the 
bud,  but  C.  7  be- 
comes situated 
deeply  in  its  sub- 
stance and  reaches 
the  surface  only  at 
the  distal  part  of 
the  limb. 

When  wounds 
or  incisions  on  the 
lateral  aspect  of 
the  forearm  heal, 
they  may  include  twigs  from  the  musculo-cutaneous  nerve 
in  the  cicatrix.  The  irritation  of  the  nerve  reflexly  stimulates 
the  segments  of  the  spinal  medulla  (C.  5  and  6)  from  which  the 


FIG.   15. — Schematic  Representation  of  the  Distribu- 
tion of  the  Spinal  Nerves  to   the  Skin   on  the 
Dorsal  Aspect  of  the  Upper  Limb. 
D.A.L.  Dorsal  axial  line. 


50  THE  SUPERIOR  EXTREMITY 

nerve  arises,  with  the  result  that  muscles  supplied  by  these 
segments — the  biceps  and  the  brachialis  (b.  anticus) — may  be 
thrown  into  spasm.  In  this  way  the  condition  of  "  Bent  Arm  " 
arises  ;  and  it  can  be  cured  only  by  excision  of  the  cicatrix. 

Superficial  Veins  of  Elbow  and  Forearm. — The  superficial  veins 
of  the  forearm  arise  from  the  plexuses  of  the  digits  and  hand,  and,  although 
liable  to  variation,  their  arrangement  at  the  elbow  is  fairly  constant.  The 
Median  Vein  begins  near  the  dorsal  radial  tubercle  (p.  46),  and  winds  round 
the  radial  border  of  the  forearm.  It  ends  at  the  apex  of  the  cubital  fossa  by 
dividing  into  the  Median  Basilic  and  Median  Cephalic  veins,  soon  after  it 
has  received  its  chief  tributary,  the  profunda,  from  the  deeper  structures  of 
the  forearm  (Fig.  12). 

The  Median  Basilic  passes  proximally  and  medially,  superficial  to  the 
lacertus  fibrosus  (bicipital  fascia),  and  in  front  of  the  medial  epicondyle  it 
joins  the  Basilic  vein,  which  ascends  from  the  ulnar  side  of  the  hand.  There- 
after the  basilic  vein  ascends  in  the  medial  bicipital  furrow  as  far  as  the 
insertion  of  the  coraco-brachialis,  where  it  pierces  the  deep  fascia  (p.  34). 
The  Cephalic  vein,  which  arises  on  the  radial  side  of  the  hand,  is  joined  by  the 
median  cephalic  in  front  of  the  lateral  epicondyle.  It  passes  proximally 
on  the  deep  fascia  over  the  lateral  aspect  of  the  biceps  brachii  and  enters  the 
groove  between  the  deltoid  and  the  pectoralis  major,  which  conducts  it  to 
the  superficial  infra-clavicular  triangle. 

It  is  important  to  recognise  that  most  of  the  venous  return  from  the  hand 
and  forearm  passes  by  the  profunda  to  the  median  and  then  to  the  basilic 
and  cephalic  veins,  which  are  superficially  placed,  whereas  only  a  small  pro- 
portion returns  by  the  vense  comites  of  the  brachial  artery. 

On  this  account  the  venous  return  is  easily  controlled,  and  the  arm  is 
therefore  suitable  for  the  purpose  of  Bier's  congestive  treatment  in  acute 
infective  conditions. 

Bandages,  too  tightly  applied,  very  easily  produce  such  oedema  and 
pressure  that  Volkmann's  ischaemic  contracture  or  even  gangrene  of  the 
limb  may  follow. 

Volkmann's  Ischsemic  Contracture  produces  a  deformity  in  which 
the  fingers  and  wrist  gradually  assume  a  flexed  attitude,  owing  to  an  inter- 
stitial fibrosis  of  the  flexor  muscles  of  the  forearm.  When  the  wrist  is 
passively  extended,  the  flexion  of  the  fingers  is  increased,  as  the  fibrosed 
flexor  muscles  cannot  stretch.  The  extensor  muscles  become  stretched 
and  weakened  by  the  constant  flexion  of  the  fingers,  and  they  appear  to  be 
paralysed.  On  flexion  of  the  wrist,  which  loosens  the  flexors  and  over- 
stretches the  extensors,  it  will  be  found  that  the  extensors  of  the  fingers  are 
able  to  produce  a  weak  movement,  a  feature  which  serves  to  differentiate 
the  condition  from  radial  (musculo-spiral)  paralysis  (p.  102). 

The  median  basilic  and  median  cephalic  are  the  veins 
commonly  used  for  transfusion  of  saline  or  for  intravenous 
injection  of  drugs.  They  may  be  rendered  prominent  by  allowing 
the  arm  to  hang  downwards  for  a  few  minutes  or  by  applying 
a  bandage  round  the  arm  tight  enough  to  constrict  the  veins 
without  affecting  the  artery. 

The  Lymph  Vessels  of  the  digits  and  hand  are  closely 
associated  with  the  superficial  veins,  and  the  main  trunks 
accompany  the  bigger  veins  in  the  forearm.  Those  of  the  ulnar 


THE  REGION  OF  THE  ELBOW        51 

side  open  into  the  epitrochlear  lymph  gland  (p.  44),  while  the 
median  and  radial  lymph  trunks  open  into  lymph  glands  which 
lie  in  the  cubital  fossa.,  or,  in  the  absence  of  these,  into  the 
epitrochlear  lymph  gland.  The  efferents  from  these  glands 
follow  the  course  of  the  basilic  vein  and  terminate  in  the 
central  group  of  the  axillary  lymph  glands  (p.  35).  Some- 
times the  lymph  vessels  from  the  lateral  three  digits  pass 
directly  along  the  radial  side  of  the  arm  and  end  in  the 
infra -clavicular  (p.  30)  or  even  in  the  pectoral  lymph 
glands  (p.  35). 

The  Elbow  and  Proximal  Radio-Ulnar  Joints.— At 
the  elbow-joint  the  Trochlea  and  Capitulum  of  the  humerus 
articulate  with  the  Semilunar  Notch  (Greater  Sigmoid  Cavity) 
of  the  ulna  and  the  proximal  surface  of  the  head  of  the  radius, 
respectively.  At  the  proximal  radio-ulnar  joint  the  medial 
side  of  the  head  of  the  radius  articulates  with  the  Radial  Notch 
(Lesser  Sigmoid  Cavity)  of  the  ulna,  and  the  cartilage  covering 
these  areas  is  directly  continuous  with  that  which  covers  the 
adjoining  articular  surfaces  of  the  humero-radial  and  humero- 
ulnar  joints. 

The  transverse  axis  of  the  trochlea  slants  distally  and 
medially,  and  is  therefore  not  at  right  angles  to  the  long  axis  of 
the  humerus.  The  semilunar  notch  (greater  sigmoid  cavity) 
is  formed  by  the  anterior  surface  of  the  olecranon  and  by  the 
proximal  surface  of  the  coronoid  process.  The  transverse  axis 
of  the  latter  forms  an  angle  of  less  than  90°  with  the  shaft  of  the 
ulna,  and  so  the  long  axis  of  the  humerus  and  ulna  meet  at  an 
angle  of  less  than  180°  when  the  forearm  is  extended  and  supine. 
This  lateral  angulation  (Fig.  16)  is  termed  the  "  Carrying 
Angle,"  and  it  allows  the  supinated  forearm  to  swing  freely  past 
the  pelvis.  It  is  masked  in  flexion  of  the  supinated  forearm 
and  in  pronation.  The  angles  which  the  long  axes  of  the 
humerus  and  ulna  make  with  the  transverse  axis  of  the  elbow 
are  equal  to  one  another.  As  a  result,  when  the  supinated 
forearm  is  fully  flexed,  the  anterior  surfaces  of  the  arm  and 
forearm  are  accurately  applied  to  one  another.  But,  when 
the  supinated  forearm  is  fully  flexed  (the  arm  being  by  the  side), 
the  palm  of  the  hand  lies  over  the  medial  half  of  the  clavicle 
and  not  over  the  point  of  the  shoulder,  owing  to  the  existing 
medial  rotation  of  the  humerus  (p.  44).  To  obtain  the  correct 
alignment  of  the  arm  and  to  reproduce  accurately  the  carrying 
angle  following  fractures  into  the  joint,  the  limb  is  adjusted 


52  THE  SUPERIOR  EXTREMITY 

with  the  arm  by  the  side,  the  forearm  fully  flexed  but  not 
quite  fully  supinated,  and  the  palm  in  front  of  the  medial  half 
of  the  clavicle. 

The    Capsule   is    attached  on  the  anterior    aspect  of  the 
humerus  to  the  proximal  borders  of  the  coronoid  and  radial 


FIG.  1 6. — Normal  Elbow  of  an  Adult  Female.  Antero-posterior  View.  The 
carrying  angle  is  well  shown.  The  increased  density  of  the  shadow  in 
the  region  of  the  trochlea  is  caused  by  the  olecranon. 

fossae  and  to  the  bases  of  the  epicondyles.  Posteriorly,  it  is 
attached  to  the  floor  of  the  olecranon  fossa,  and  to  its  sides 
as  far  as  the  bases  of  the  epicondyles.  On  the  ulna  it  is  attached 
to  the  margins  of  the  semilunar  notch,  except  at  the  radial 
notch.  On  the  lateral  aspect  of  the  joint  it  blends  with  the 
annular  ligament. 


THE  REGION  OF  THE  ELBOW 


53 


The  Annular  (Orbicular)  Ligament  surrounds  the  head  of 
the  radius  and  is  attached  to  the  anterior  and  posterior 
extremities  of  the  radial  notch.  Its  proximal  border  blends 
with  the  capsule  of  the  elbow,  but  its  distal  margin  is  not  attached 
to  bone,  and  therefore  the  distal  part  of  the  capsule  of  the  elbow 
and  proximal  radio-ulnar  joints  is  incomplete.  Through  the 
gap  left  between  the  neck  of  the  radius  and  the  distal  border 
of  the  annular  ligament  the  synovial  membrane  pouches  distally 
for  a  varying  distance  (Fig.  17). 

The  Anterior  and  Posterior  Ligaments  of  the  elbow  are 


paM: 
m®£-  •'•^^:' 

Medial  epicondyle-jf-'fif'      -  • 
Epiphyseal  lines 


Distal  epiphysis 

of  humerus 

Ulnar  col  lateral  - 

ligament 


Radial  collateral 
ligament 


Annular  ligament 
Head  of  radius 
Epiphyseal  line 

Protrusion  of 
ynovial  membrane 


FIG.  17. — Frontal  Section  through  the  Elbow  and  Proximal 
Radio-Ulnar  Joints. 


Light  blue  =  articular  cartilage. 
Striped  blue  =  ligaments. 


Green  =  periosteum. 

Red  =  synovial  membrane. 


simply  thickenings  of  the  capsule  in  front  and  behind.  They 
do  not  possess  great  strength,  but  they  are  supported  by  the 
tendons  of  the  brachialis  and  the  triceps  respectively. 

The  Radial  Collateral  (External  Lateral)  Ligament  is 
narrow  at  its  attachment  to  the  lateral  epicondyle  but  is  wider 
distally,  where  it  blends  with  the  annular  ligament. 

The  Ulnar  Collateral  (Internal  Lateral)  Ligament  is 
attached  to  the  distal  aspect  of  the  medial  epicondyle.  Its 
anterior  fibres  pass  to  the  medial  border  of  the  coronoid  process 
and  its  posterior  fibres  to  the  medial  border  of  the  olecranon, 
while  the  intermediate  fibres  are  attached  to  a  strong  transverse 
band  which  bridges  the  interval  between  the  two  processes. 

4a 


54 


THE  SUPERIOR  EXTREMITY 


The  Synovial  Membrane  is  attached  to  the  margins  of  the 
articular  cartilages  of  the  humerus,  ulna,  and  radius.  It  then 
covers  the  adjacent  bone  as  far  as  the  attachment  of  the  fibrous 
capsule,  on  to  which  it  is  reflected.  At  the  distal  border  of  the 
annular  ligament  of  the  radius  the  membrane  pouches  down- 
wards for  a  short  distance  around  the  neck  of  the  bone.  Little 
pads  of  fat  fill  up  the  olecranon,  coronoid,  and  radial  fossae,, 


Posterior  ligament 
Pad  of  fat 

Anterior  ligament 

Epiphyseal  line 

Pad  of  fat 

Trochlea  of 
humerus 

Triceps  tend 
Bursa  under  triceps 


Olecranon  V"Y" 
Epiphyseal  line  X— 


Olecranon  bursa 


FIG.  1 8.— Sagittal  Section  through  the  Elbow  Joint.  The  synovial  mem- 
brane lining  the  joint  is  shown  in  red,  the  articular  cartilage  in  light 
blue,  and  the  periosteum  in  green.  The  pads  of  fat,  though  intra- 
capsular,  are  extra-synovial. 

but  although  they  are  intra-capsular  they  are  covered  by  the 
synovial  membrane  and  therefore  remain  extra-synovial  (Fig. 
1 8).  When  these  fatty  pads  hypertrophy  (lipoma  arborescens), 
portions  of  them  may  project  into  the  joint ,  but  they  are  still 
covered  by  a  layer  of  synovial  membrane. 

The  Nerve  Supply  of  the  joint  is  derived  from  branches  of 
the  Ulnar,  Median,  Radial  (Musculo-spiral),  and  Musculo- 
cutaneous  nerves. 

The  presence  of  fluid  in  the  joint  is  apparent  first  on  either 
side  of  the  tendon  of  the  triceps,  owing  to  the  weakness  of  the 


THE  REGION  OF  THE  ELBOW  55 

posterior  part  of  the  capsule,  and,  subsequently,  the  dimple 
proximal  to  the  head  of  the  radius  becomes  obliterated.  The 
deep  fascia  on  the  front  of  the  elbow  and  the  lacertus  fibrosus 
(bicipital  fascia)  are  exceptionally  strong,  and  therefore,  if 


FIG.  19. — Elbow  of  Child,  aged  four.  Lateral  View.  The  centre  of  ossifica- 
tion for  the  capitulum  is  the  only  secondary  centre  present.  It  lies  on  a 
plane  anterior  to  the  long  axis  of  the  humerus.  A  tuberculous  focus  is 
seen  in  the  proximal  part  of  the  shaft  of  the  ulna. 

sinuses  develop  in  connection  with  the  joint,  they  will  usually 
be  found  on  one  or  other  side  of  the  triceps  tendon. 

The  elbow-joint  may  be  aspirated  by  inserting  a  trochar 
from  the  lateral  side,  at  right  angles  to  the  limb,  immediately 
proximal  to  the  head  of  the  radius. 

Ossification  of  the  Distal  Extremity  of  the  Humerus.— 
In  the  infant  the  whole  of  the  distal  extremity  of  the  humerus 


56  THE  SUPERIOR  EXTREMITY 

is  cartilaginous.  During  the  second  or  third  year  a  secondary 
centre  appears  for  the  Capitulum  and  lateral  part  of  the  Trochlea, 
and  this  is  followed,  about  the  fifth  year,  by  the  centre  for  the 
Medial  Epicondyle.  At  this  period  the  distal  and  medial  part 


FIG.    20. — Elbow  Joint  of  Boy,  aged  fourteen.      The  centres  of  ossification 
in  the  distal  extremity  of  the  humerus  are  well  shown. 

of  the  diaphysis  grows  distally,  separating  the  Medial  Epicondyle 
from  the  rest  of  the  Epiphysis  (Fig.  17).  During  the  eleventh 
and  twelfth  years  centres  appear  for  the  Lateral  Epicondyle 
and  the  remainder  of  the  Trochlea.  The  true  epiphysis  consists 
of  the  three  lateral  centres  of  ossification,  which  fuse  with  one 
another  at  thirteen  or  fourteen,  and  it  joins  the  shaft  between 


THE  REGION  OF  THE  ELBOW 


57 


the  sixteenth  and  seventeenth  years.  The  actual  line  of  union 
corresponds  to  the  proximal  margin  of  the  articular  cartilage 
and  laterally  from  the  point  at  which  the  cartilage  ceases,  to  a 


FIG.  21. — Elbow  of  Child,  aged  five.  The  centres  of  ossification  for  the 
capitulum  and  for  the  head  of  the  radius  can  be  recognised,  but  the 
medial  epicondyle  has  not  yet  begun  to  ossify. 

point  immediately  proximal  to  the  lateral  epicondyle ;  on  the 
medial  side  it  coincides  with  the  margin  of  the  trochlea  (Fig.  18). 
The  medial  epicondylar  epiphysis  joins  the  diaphysis  about  one 
year  later. 


58  THE  SUPERIOR  EXTREMITY 

Ossification  of  the  Proximal  Extremity  of  the  Ulna.— 
The  formation  of  the  olecranon  is  due  chiefly  to  the  growth  of 
the  diaphysis  which  occurs  during  childhood.  A  secondary 
centre  appears  in  the  cartilaginous  extremity  about  the  eighth 
or  ninth  year.  It  forms  the  proximal  portion  of  the  olecranon 
(Fig.  1 8),  but,  as  a  rule,  it  takes  no  part  in  the  formation  of  the 
articular  surface  of  the  semilunar  notch  (greater  sigmoid  cavity). 
It  joins  the  shaft  about  the  seventeenth  year. 

Dislocation  of  the  elbow  is  common  in  childhood;  because 
the  bony  prominences,  which  in  adults  produce  an  osseously 
strong  joint,  are  only  developing  at  that  period. 

Ossification  of  the  Proximal  Extremity  of  the  Radius.— 
In  the  cartilaginous  proximal  extremity  of  the  radius  a  secondary 
centre  appears  between  four  and  five,  and  forms  a  disc-shaped 
epiphysis,  which  joins  the  shaft  between  eighteen  and  twenty. 
Until  this  centre  begins  to  enlarge,  there  is  relatively  little 
difference  between  the  circumferences  of  the  head  and  the  neck 
of  the  bone.  This  fact  explains  the  frequency  of  subluxation 
of  the  radius  (p.  62)  in  little  children. 

The  various  epiphyses  of  the  elbow  have  been  described  in 
some  detail,  as  a  thorough  knowledge  of  them  is  necessary  for 
the  correct  interpretation  of  radiograms  of  this  region.  It  is  not 
uncommon  for  the  clear  area  of  epiphyseal  cartilage  to  be  mis- 
taken for  the  line  of  a  fracture,  if  there  is  any  history  of  injury ; 
and  the  olecranon  has  been  cut  down  upon  owing  to  this  error. 

Separation  of  the  Epiphysis  at  the  distal  end  of  the 
humerus  is  the  commonest  of  the  more  severe  injuries  of  the 
elbow  region  which  occur  during  childhood  and  adolescence. 
It  may  be  complicated  by  fracture  across  the  distal  and  medial 
portion  of  the  diaphysis.  The  displacement  of  the  distal 
fragment  is  usually  backwards,  and,  owing  to  the  exceedingly 
strong  attachment  of  periosteum  to  epiphyseal  cartilage,  the 
periosteum  is  stripped  up  from  the  posterior  aspect  of  the  distal 
part  of  the  diaphysis  for  a  varying  distance.  Unless  the 
replacement  is  accurate,  the  stripped  periosteum  forms  a  new 
shaft  to  the  humerus  posterior  to  the  existing  one,  which  remains 
as  a  prominent  exostosis  (Fig.  22),  and  subsequently  interferes 
with  flexion  by  impinging  on  the  coronoid  process.  As  the 
cartilaginous  extremity  is  translucent  to  the  X-rays,  there  may 
be  great  difficulty  in  diagnosing  this  condition  in  children  of  less 
than  three  years  of  age,  i.e.  before  the  secondary  ossific  centres 
are  present. 


THE  REGION  OF  THE  ELBOW 


59 


Spread  of  Tuberculous  Osteo  -  Myelitis  in  the  Elbow 
Region. — A  focus  of  tubercle  situated  in  the  growing  region  of 
the  diaphysis  of  the  distal  extremity  of  the  humerus  is  intra- 
capsular.  It  may  spread  (i)  towards  the  medullary  cavity  ; 


FIG.  22. — Elbow  of  Child,  aged  five.  Lateral  View.  The  condition  shown 
is  subsequent  to  separation  of  the  distal  humeral  epiphysis,  in  which  the 
periosteum  had  been  stripped  up  from  the  posterior  surface  of  the 
diaphysis.  Owing  to  malposition  of  the  fragments,  a  new  shaft  has  been 
formed  on  a  posterior  plane. 

(2)  distally,  through  the  epiphyseal  cartilage,  into  the  epiphysis, 
to  erupt  subsequently  through  the  articular  cartilage  into  the 
joint ;  or  (3)  if  the  focus  increases  in  all  directions,  it  will,  in 
spite  of  the  reaction  of  the  periosteum,  perforate  that  membrane 
where  it  lines  one  of  the  humeral  fossae.  The  disease  is  then 
intra-capsular  but  extra-synovial,  and  is  in  direct  relation  to 


6o  THE  SUPERIOR  EXTREMITY 

the  extra -sy  no  vial  pads  of  fat  (p.  54).  It  rapidly  involves 
the  sy  no  vial  membrane  and  attacks  the  joint.  The  last- 
mentioned  is  the  usual  direction  of  spread  (Stiles).  When  a 
focus  is  recognised  before  it  has  penetrated  the  periosteum,  the 
distal  part  of  the  diaphysis  may  be  resected  subperiosteally, 
without  the  joint  being  opened. 

Surgical  Approach  to  the  Distal  Part  of  the  Humerus. — 
In  subperiosteal  resection  of  the  distal  part  of  the  shaft  of  the 
humerus  for  tuberculous  disease,  the  bone  is  approached  on  the 
postero-lateral  aspect  of  the  arm.  The  incision  extends  from 
just  below  the  radial  (musculo-spiral)  groove  to  the  lateral 
epicondyle.  The  medial  head  of  the  triceps  is  split  and  the 
bone  is  exposed.  After  the  periosteum  has  been  separated, 
the  humerus  is  cut  through  at  a  level  proximal  to  the  disease, 
and  the  distal  part  of  the  diaphysis  is  wrenched  out.  The  bone 
tears  away  from  the  epiphyseal  cartilage,  which  is  left  attached 
to  the  epiphysis.  Although  the  capsule  is  attached  to  the 
periosteum  beyond  the  epiphyseal  line,  the  elbow-joint  is  not 
opened  because  the  periosteum  is  firmly  attached  to  the 
epiphyseal  cartilage. 

When  a  tuberculous  focus  occurs  in  the  Proximal  Extremity 
of  the  Radial  Diaphysis,  it  is  intra-capsular .  Any  extension 
of  the  disease  through  the  periosteum  of  the  neck  will  certainly 
infect  the  synovial  membrane  of  the  elbow-joint,  on  account 
of  the  relations  which  these  structures  bear  to  one  another 
(Fig.  17).  Extension  in  a  distal  direction  will  involve  the  shaft. 
(See  p.  75  for  resection  of  proximal  part  of  radius.) 

A  tuberculous  focus  in  the  Proximal  End  of  the  Ulna  is 
extra-capsular.  It  may  spread  (i)  forwards  through  the  articular 
cartilage  into  the  joint ;  (2)  distally  into  the  shaft,  or  (3)  it  may 
perforate  the  periosteum  on  the  lateral  or  medial  side  of  the 
bone  and  infect  the  soft  parts.  The  last  mentioned  is  the 
commonest  direction  of  spread. 

The  proximal  end  of  the  ulna  is  unsuitable  for  complete  sub- 
periosteal resection  as,  by  removal  of  the  shaft  and  semilunar 
notch  (greater  sigmoid  cavity),  the  elbow-joint  is  widely  opened. 

Dislocation  Of  the  Elbow.— (a)  Posterior.— This  injury 
results  from  a  fall  on  the  hand,  the  arm  being  abducted  at  the 
shoulder  and  extended  at  the  elbow.  The  line  of  force  passes 
upwards  behind  the  transverse  axis  of  the  elbow-joint,  and,  as 
a  result,  the  forearm  is  hyper-extended.  All  the  ligaments 
give  way,  except  the  annular  (orbicular),  and  the  distal  extremity 


THE  REGION  OF  THE  ELBOW        61 

of  the  humerus  slips  forwards  out  of  the  semilunar  notch.  The 
coronoid  process  comes  to  rest  in  the  olecranon  fossa  ;  the  head 
of  the  radius  lies  behind  the  lateral  epicondyle  ;  and  the  distal 
end  of  the  humerus  sinks  into  the  cubital  fossa.  The  arm  and 
forearm  meet  at  an  angle  of  about  120°,,  but  in  old-standing 
cases  the  angle  becomes  less  pronounced  owing  to  the  constant 
traction  of  the  triceps.  The  relations  of  the  epicondyles  to  one 
another  are  unchanged,  but  their  relations  to  the  other  bony 
points  undergo  considerable  alteration. 

(b)  Anterior. — This  rare  dislocation  results  from  violence, 
applied  to  the  olecranon  from  behind  when  the  elbow  is  flexed. 
The  triceps  is  ruptured  and  the  radius  and  ulna  pass  forwards, 
the  forearm  being  flexed  by  the  brachialis  and  the  biceps.     All 
the  ligaments  except  the  annular  (orbicular)  are  torn,  and  the 
muscles  arising  from  the  epicondyles  may  be  injured.     Compared 
with  the  sound  limb,  there  is  an  increase  in  the  distance  between 
the  lateral  epicondyle  of  the  humerus  and  the  styloid  process 
of  the  radius. 

An  incomplete  variety  of  this  dislocation  occurs  when  the 
injury  is  complicated  by  fracture  of  the  olecranon.  The  small 
fragment  remains  in  contact  with  the  trochlea,  but  the  remainder 
of  the  ulna  and  the  radius  pass  forwards  in  front  of  the  distal 
end  of  the  humerus. 

(c)  Lateral  and  (d)  Medial  dislocations  occur  from  falls 
upon  the  pronated,  outstretched  hand.     The  direction  of  the 
displacement  depends  on  whether  the  line  of  force  is  lateral  or 
medial  to  the  mid-point  of  the  transverse  axis  of  the  elbow. 

The  lateral  dislocation  may  be  complete,  and,  if  so,  all  the 
ligaments,  except  the  annular,  are  ruptured.  More  commonly 
the  semilunar  notch  does  not  entirely  leave  the  trochlea,  and 
the  dislocation  is  consequently  incomplete. 

The  medial  dislocation  is  always  incomplete,  as  the  head  of 
the  radius  remains  partially  in  contact  with  the  capitulum, 
though  at  a  different  angle,  as  the  long  axis  of  the  bone  is  now 
directed  distally  and  medially. 

Divergent  dislocations  can  occur  only  after  rupture  of  the 
annular  (orbicular)  ligament.  They  may  be  either  antero- 
posterior,  the  radius  passing  forwards  and  the  ulna  backwards, 
or  they  may  be  horizontal,  the  radius  being  displaced  laterally 
and  the  ulna  medially. 

Reduction  of  the  posterior  dislocation  may  be  performed 
by  traction  on  the  forearm  and  counter-extension  of  the  arm. 


62  THE  SUPERIOR  EXTREMITY 

As  soon  as  the  coronoid  process  is  drawn  past  the  distal  surface 
of  the  trochlea,  the  forearm  is  flexed,  as  the  displacement  will 
not  recur  with  the  elbow  in  this  position.  If  the  coronoid 
process  hitches  in  the  olecranon  fossa,  the  forearm  may  be 
hyper-extended,,  and,  by  using  the  tip  of  the  olecranon  as  a 
fulcrum  against  the  distal  end  of  the  humerus,  the  coronoid  is 
lifted  out  of  the  olecranon  fossa.  It  can  then  be  drawn  distally 
by  traction. 

In  children,  reduction  is  easily  obtained  (p.  58)  if  the  surgeon 
grasps  the  arm  just  proximal  to  the  epicondyles  in  such  a  way 
that  he  can  exert  the  pressure  of  both  thumbs  to  push  the 
olecranon  downwards. 

The  spasm  of  the  brachialis  assists  in  the  replacement,  as 
soon  as  the  tension  of  the  triceps  is  overcome. 

Complications. — The  Ulnar  Nerve  may  be  stretched  or 
bruised  at  the  time  of  dislocation,  especially  if  the  medial 
epicondyle  is  broken  off  (p.  63). 

Fracture  of  the  Coronoid  Process  may  complicate  the 
posterior  dislocation.  Reduction  is  easy,  but  the  displacement 
readily  recurs.  The  injury  may  be  mistaken  for  a  supracondylar 
fracture  of  the  humerus,  unless  the  relations  of  the  bony  points 
are' carefully  studied. 

Fracture  of  the  Epicondyles  (p.  63). 

Myositis  ossificans  in  the  tendon  of  the  brachialis  is  a 
complication  which  not  uncommonly  follows  dislocation  of  the 
elbow.  The  osseous  deposit  interferes  with  complete  flexion 
and  may  or  may  not  remain  permanently. 

Subluxation  of  the  Radius  (p.  58)  is  produced  by  sudden 
traction  on  the  hand  or  wrist.  It  is  probable  that  only  a  part 
of  the  head  of  the  radius  slips  out  of  the  annular  (orbicular) 
ligament ;  otherwise  reduction  would  be  difficult  to  obtain. 
When  the  accident  occurs,  the  forearm  is  in  the  position  of 
pronation  and  the  greatest  strain  is  thrown,  through  the  radius, 
on  to  the  lateral  part  of  the  annular  ligament.  This  oblique 
strain  drags  the  postero-lateral  part  of  the  head  of  the  radius 
through  the  ligament,  leaving  the  medial  half  of  the  head  within 
the  joint.  Complete  downward  subluxation  is  prevented  by 
the  interosseous  membrane  and  the  ligaments  of  the  distal 
radio-ulnar  joint,  and  can  occur  only  when  these  ligaments  are 
injured.  The  forcible  supination,  carried  out  by  the  surgeon, 
screws  the  half-dislocated  head  back  into  place  again. 

Fractures  around  the  Elbow-Joint.— The  distal  end 


THE  REGION  OF  THE  ELBOW        63 

of  the  humerus  is  weakened  by  the  grooving  of  the  trochlea  and 
by  the  olecranon  and  coronoid  fossae.  It  has  to  withstand  the 
force  transmitted  through  the  forearm  from  falls  upon  the  hand, 
and  in  consequence  fractures  in  this  situation  are  very  common. 

In  children,  the  injury  may  take  the  form  of  a  Separation 
of  the  Distal  Epiphysis  of  the  Humerus.  In  adults,  the 
supracondylar  fracture  of  the  shaft  frequently  radiates  through 
one  of  the  fossae  into  the  joint,  giving  rise  to  the  so-called  T-  or 
Y-shaped  fracture. 

The  medial  epicondyle  may  be  fractured  without  other 
injuries.  It  is  displaced  distally  and  forwards  by  the  attached 
flexor  and  pronator  muscles.  Sometimes  the  line  of  this  fracture 
is  oblique  and  includes  a  portion  of  the  trochlea  in  addition, 
consequently  involving  the  joint.  Through  faulty  apposition 
the  medial  epicondyle  may  be  displaced  proximally,  changing 
the  transverse  axis  of  the  trochlea  (p.  51),  and  subsequently 
leading  to  the  condition  of  cubitus  varus. 

This  injury  may  involve  the  ulnar  nerve,  causing  neuritis 
and  progressive  paresis  of  the  muscles  which  it  supplies  (p.  104). 
Occasionally  the  symptoms  do  not  appear  till  many  years  later, 
and  evidence  of  injury,  of  which  there  is  often  no  history,  is 
obtained  only  by  the  X-rays. 

Injury  to  the  lateral  epicondyle  may  lead  in  the  same  way 
to  the  condition  of  cubitus  valgus  (see  Carrying  Angle,  p.  51). 

Fracture  of  the  Olecranon  Process. — The  small,  proximal 
fragment  usually  includes  the  proximal  half  of  the  semilunar 
notch,  and,  consequently,  the  joint  cavity  of  the  elbow  is 
involved  (Fig.  18).  The  swelling,  which  is  partly  due  to  the 
violence,  is  increased  by  haemorrhagic  extravasation  into  the 
joint,  and  it  may  press  upon  the  superficial  veins,  producing 
cedema  of  the  forearm  and  hand.  There  may  be  little  or  no 
separation  of  the  fragments,  in  which  case  they  are  kept  in 
position  by  the  periosteum,  the  ulnar  collateral  (internal  lateral) 
ligament  of  the  elbow,  the  anconaeus,  and  the  common  ulnar 
aponeurosis.  When  wide  separation  occurs,  the  proximal 
fragment  is  drawn  proximally  and  backwards  by  the  triceps, 
and  difficulty  is  experienced  in  keeping  the  ends  in  good 
apposition.  On  this  account  the  surgeon  frequently  has  recourse 
to  the  operation  of  wiring.  The  fragments  can  be  brought 
together  by  two  wires — one  vertical,  the  other  transverse — 
without  interfering  with  the  articular  surface  (Fig.  23). 

Fracture  of  the  Neck  of  the  Radius  is  a  rare  accident, 


64  THE  SUPERIOR  EXTREMITY 

and  it  is  difficult  to  treat  owing  to  the  lack  of  fixation  of  the 
head  (p.  53);  which  may  become  a  loose  body  in  the  elbow-joint. 
On  pronation  and  supination,  the  head  of  the  radius  does  not 
rotate  in  the  annular  ligament,,  and  the  muscles  are  thrown  into 
spasm.  Owing  to  non-union  or  to  faulty  union,  movements  of 
the  elbow  may  be  so  restricted  that  excision  of  the  head  of  the 


FIG.   23. — Elbow  of  an  Adult  Male,  showing  a  Fracture  of  the  Olecranon, 
wired  in  Two  Planes.      Note  that  the  wires  do  not  invade  the  joint  cavity. 

bone  is  rendered  necessary.  It  may  be  approached  by  a 
longitudinal  incision  over  the  interval  between  the  anconaeus 
and  the  extensor  carpi  ulnaris  (Fig.  26). 

Many  of  the  fractures  in  this  region  are  both  intra-  and 
extra-capsular,  and  the  haemorrhage  and  effusion  into  the  joint 
render  their  diagnosis  difficult,  even  with  the  assistance  of  the 
X-rays. 

Surgical  Approach  to  the  Elbow- Joint. — Kocher's  lateral 


THE  FOREARM  AND  WRIST  65 

J -shaped  incision  is  probably  the  best,  since  it  is  planned  so  as 
to  do  least  damage  and  yet  gives  good  preliminary  exposure. 
Proximally,  the  incision  lies  immediately  behind  the  lateral 
intermuscular  septum  and  the  radial  collateral  (external  lateral) 
ligament,  and,  below,  it  follows  the  distal  border  of  the  anconseus 
to  the  ulna.  The  annular  ligament  is  cut  through  on  its  lateral 
aspect  and  the  joint  is  opened. 

If  the  subperiosteal  method  of  resection  is  adopted,  large 
portions  of  the  removed  shafts  will  be  reproduced.  Some 
shortening  of  the  limb  may  follow,  but  growth  is  most  active 
and  most  prolonged  at  the  shoulder  and  wrist,  and  consequently, 
the  results  of  removal  of  the  epiphyses  at  the  elbow  are  not  so 
serious  as  might  be  expected.  The  flap,  which  consists  of  the 
skin,  fascia,  triceps,  and  anconseus,  is  elevated  subperiosteally 
from  the  humerus  and  the  ulna  until  the  ulnar  collateral  liga- 
ment is  freed.  After  the  radial  collateral  ligament  has  been 
dealt  with  similarly,  the  olecranon  is  removed.  In  this  way 
the  joint  is  widely  exposed.  In  dealing  with  the  neck  of  the 
radius,  care  must  be  taken  lest  the  deep  branch  of  the  radial 
nerve  (posterior  interosseous  nerve)  should  be  injured  in  its 
passage  through  the  supinator  (s.  brevis),  and  the  dependent 
pouch  of  the  synovial  membrane  in  this  situation  (Fig.  17) 
must  be  totally  extirpated.  The  synovial  membrane  covering 
the  fatty  pads  (p.  54  )  which  fill  up  the  humeral  fossae  is  also 
completely  removed.  In  this  operation  the  ulnar  nerve  is  not 
exposed,  if  the  subperiosteal  excision  is  employed. 


THE  FOREARM  AND  WRIST. 

Bony  Landmarks.— The  proximal  part  of  the  shaft  of  the 
Radius  is  surrounded  by  muscles,  but  the  distal  part  of  its 
lateral  surface  and  most  of  its  distal  extremity  can  be 
readily  examined.  The  anterior  border  of  its  distal  end 
can  be  made  out  as  a  distinct  ridge  on  the  front  of  the  forearm 
about  an  inch  from  the  thenar  eminence.  In  the  hollow 
immediately  proximal  to  this  ridge  the  radial  artery  can  be 
felt  pulsating,  and  it  may  be  compressed  backwards  against 
the  bone.  The  radial  ridge  can  be  traced  laterally  till  it  joins 
the  sharp  volar  (anterior)  margin  of  the  bone.  When  the 

5 


66  THE  SUPERIOR  EXTREMITY 

thumb  is  extended,  the  tendons  of  the  abductor  pollicis  longus 
(ext.  oss.  metacarp.)  and  the  extensor  pollicis  brevis  can  be  felt 
on  the  radial  side  of  the  wrist,  and  when  the  tendons  are  relaxed, 
the  apex  of  the  Styloid  Process  of  the  radius  is  found  under 
cover  of  them,  half  an  inch  distal  to  the  radial  ridge.  A  tubercle 
(of  Lister)  is  situated  on  the  dorsal  aspect  of  the  distal  end  of 
the  radius,  in  the  line  of  the  cleft  between  the  index  and  middle 
fingers. 

The  Dorsal  Border  of  the  Ulna  is  subcutaneous  throughout 
its  whole  extent,  and,  in  muscular  subjects,  its  position  is 
indicated  by  a  furrow.  The  Styloid  Process  of  the  Ulna  can 
be  found  by  tracing  the  dorsal  border  distally.  It  is  placed  on 
the  postero-medial  aspect  of  the  head  and  lies  from  a  quarter 
to  half  an  inch  proximal  to  the  styloid  process  of  the  radius. 
It  corresponds  to  the  level  of  the  wrist -joint.  When  the  hand 
is  flexed,  the  rounded  Head  of  the  Ulna  can  be  felt  just  proximal 
to  the  level  of  the  radial  ridge  by  displacing  the  tendon  of  the 
flexor  carpi  ulnaris  either  to  the  ulnar  or  to  the  radial  side. 
When  the  hand  is  prone,  the  lateral  surface  of  the  head  stands 
out  prominently  on  the  ulnar  side  of  the  back  of  the  wrist. 

The  Tubercle  of  the  Navicular  (Scaphoid)  is  felt  about 
three-quarters  of  an  inch  distal  to  the  radial  ridge  at  the  proximal 
border  of  the  thenar  eminence.  If  the  most  distal  skin  crease 
at  the  wrist  is  followed,  it  will  be  found  to  cross  the  tubercle 
of  the  navicular,  on  the  radial  side,  and  the  Pisiform  Bone,  on 
the  ulnar  side.  This  latter  bone  is  most  easily  identified  by 
allowing  the  hand  to  hang  in  a  passively  flexed  position  to 
relax  the  flexor  carpi  ulnaris,  as  it  may  then  be  pinched  between 
the  examining  finger  and  thumb  and  made  to  glide  on  the  os 
triquetrum  (cuneiform).  The  Hook  of  the  Hamate  (Unciform) 
lies  one  finger's  breadth  distal  to  the  pisiform  and  on  a  line  with 
the  ulnar  border  of  the  ring  finger.  On  deep  palpation  the 
superficial  division  of  the  ulnar  nerve  may  be  rolled  to  and  fro 
over  the  prominence.  The  Ridge  on  the  Os  Multangulum 
Majus  (Trapezium)  is  placed  immediately  distal  to  the  navicular 
tubercle. 

Muscular  Landmarks. — The  muscular  mass  inthe  proximal 
and  lateral  part  of  the  forearm  consists  of  the  Brachio-Radialis 
and  the  Extensor  Carpi  Radialis  Longus  and  Brevis,  which 
arise  from  the  lateral  epicondylic  ridge  and  the  lateral  epicondyle. 
The  medial  margin  of  this  group  is  indicated  by  a  line  drawn 
from  the  tendon  of  the  biceps  to  the  styloid  process  of  the 


THE  FOREARM  AND  WRIST 


67 


radius.  When  resistance  is  offered  to  flexion  of  the  elbow, 
the  brachio-radialis  stands  out  prominently  on  the  lateral 
aspect  of  the  forearm. 

The  individual  Flexor  and  Pronator  muscles  cannot  be 
clearly  distinguished  proximally,  as  they  are  closely  bound 
together  by  the  deep  fascia.  Nearer  the  wrist,  however,  certain 
of  the  tendons  provide  important  surgical  landmarks.  The 
largest  and  most  prominent  tendon  is  that  of  the  Flexor  Carpi 
Radialis,  which  lies  just  medial  to  the  navicular  tubercle.  In 
flexion  of  the  wrist  the  Palmaris  Longus  tendon,  absent  in 
10  per  cent,  stands  out  on  the  ulnar  side  of  the  flexor  carpi 
radialis.  It  is  the  guide  to  the  median  nerve,  which  lies 
immediately  behind  it,  or  to  its  radial  side,  in  the  distal  part  of 
the  forearm.  The  tendon  of  the  Flexor  Carpi  Ulnaris  can  be 
gripped  between  the  fingers  and  thumb  by  inserting  the  fingers 
on  the  medial  border  of  the  forearm  opposite  the  distal  end  of 
the  ulna.  It  may  then  be  traced  to  its  insertion  into  the  pisiform 
bone. 

A  line  drawn  from  the  lateral  epicondyle  to  the  dorsal  radial 
tubercle  demarcates  the  Radial  Extensors  of  the  Wrist  from 


Insertion 
of  deltoid 


Head  of  radius     Extensor  carpi  radialis  longus 

Lateral          |       |      Dorsal  interosse- 
epicondyle      .       !      ous  nerve  Abductor 

;     ;      :  I  Extensor  carpi  pollicis 

radialis  brevis   longus 


Radial  nerve 
Triceps,  lateral  head 

Tendon  of  triceps 

Olecrano 


Head  of  ulna 
:     Extensor  carpi  ulnaris 
;    Dorsal  border  of  ulna 
!      Flexor  carpi  ulnaris  and 
]      flexor  digitorum  profundus 
Anconoeus 


FIG.  24. — Surface  Landmarks  on  the  Dorsal  Aspect  of  the 
Superior  Extremity. 

the  Extensor  Digitorum  Communis.  One  inch  from  its 
proximal  extremity,  it  crosses  the  head  of  the  radius,  and  at  a 
point  two  inches  lower  down,  the  dorsal  interosseous  nerve 
emerges  from  the  substance  of  the  supinator  (brevis).  In  its 
distal  third,  the  line  is  crossed  obliquely  by  the  muscular  bellies 
of  the  Abductor  Pollicis  Longus  (Ext.  Oss.  Metacarp.)  and 
the  Extensor  Pollicis  Brevis.  These  muscles  lie  superficial 
to  the  radial  extensor  tendons  of  the  wrist  and  are  thrown  into 
relief  on  dorsi-flexion  of  the  hand. 


68  THE  SUPERIOR  EXTREMITY 

On  the  lateral  aspect  of  the  wrist,  a  triangular  depression  is 
visible  when  the  thumb  is  extended.  It  is  bounded  antero- 
laterally  by  the  tendons  of  the  Abductor  Pollicis  Longus  and 
the  Extensor  Pollicis  Brevis  and  dorso-medially  by  the 
Extensor  Pollicis  Longus.  The  floor  of  this  fossa  is  crossed 
obliquely  by  the  second  part  of  the  radial  artery  (p.  92). 

On  the  back  of  the  wrist  the  tendons  of  the  Extensor  Carpi 
Radialis  Longus  and  Brevis  can  be  seen  when  the  fist  is  tightly 
clenched,  and  they  can  be  traced  to  their  insertions  into  the 
bases  of  the  second  and  third  metacarpal  bones  respectively. 

Muscles  of  the  Forearm  and  their  Relations  to 
Fractures. — The  superficial  group  of  flexors  and  pronators 
arises  mainly  from  the  medial  epicondyle  of  the  humerus.  They 
pass  with  varying  degrees  of  obliquity  down  the  forearm  and 
are  all,  with  the  exception  of  the  flexor  carpi  ulnaris,  supplied 
by  branches  given  off  from  the  trunk  of  the  Median  Nerve 
(C.  6),  just  distal  to  the  elbow-joint. 

The  Pronator  Teres,  which  has  in  addition  a  deep  head  of 
origin  from  the  coronoid  process,  is  the  most  lateral  and  most 
obliquely  directed  of  this  group.  It  is  inserted  into  the  middle 
of  the  lateral  surface  of  the  radius  and  is  thus  a  powerful  pronator 
of  the  forearm,  while  it  is  also  a  flexor  of  the  elbow.  In  tennis- 
players  this  muscle  is  frequently  overstretched  or  strained. 

Fractures  of  the  Bones  of  the  Forearm.— Fractures 
from  indirect  violence  may  affect  both  bones  or  the  radius  alone. 
They  occur  from  falls  on  the  hand,  and  only  a  small  part  of  the 
shock  is  directly  transmitted  to  the  ulna.  The  greater  part  is 
communicated  to  the  expanded  distal  end  of  the  radius  and 
passes  upwards  to  the  humerus.  Only  a  small  degree  of  the 
shock  is  transmitted  from  the  radius  to  the  ulna  by  the 
interosseous  membrane,  the  fibres  of  which  are  mainly  directed 
distally  and  medially.  Fracture  of  the  shaft  of  the  ulna  alone 
is  always  due  to  direct  violence  and  tends  to  be  compound,  as 
the  dorsal  border  of  the  bone  is  subcutaneous  in  its  whole 
extent. 

In  Fractures  between  the  Radial  (Bicipital)  Tuberosity 
and  the  Insertion  of  the  Pronator  Teres,  the  small  proximal 
fragment  is  flexed  and  supinated  by  the  biceps.  The  distal 
fragment  is  pronated  by  the  pronator  muscles  and  its  proximal 
end  is  tilted  towards  the  ulna  by  the  brachio-radialis  and  the 
pronator  teres.  The  proximal  fragment  is  difficult  to  control 
owing  to  its  small  size,  and  it  is  necessary  to  bring  the  distal 


THE  FOREARM  AND  WRIST  69 

fragment  into  line  with  it  by  flexing  the  elbow  and  supinating 
the  hand. 

In  Fractures  immediately  Distal  to  the  Insertion  of  the 
Pronator  Teres,  the  proximal  fragment  is  pronated  and  slightly 
flexed.  The  supinating  action  of  the  biceps  is  counteracted 
by  the  pronator  teres,  which  acts  at  a  greater  mechanical 
advantage.  The  distal  fragment  is  pronated  by  the  pronator 
quadratus,  and  its  proximal  end  is  tilted  towards  the  ulna  as 
in  the  previous  fracture.  In  this  case  the  proximal  fragment 
is  long  enough  to  be  controlled,,  and  the  forearm  is  put  up  in  the 
mid-prone  position,  since  the  distance  between  the  ulna  and 
radius  is  normally  greatest  in  this  position.  Dinar  flexion  of 
the  hand  helps  to  tilt  the  proximal  end  of  the  distal  fragment 
away  from  the  ulna. 

The  Superficial  Muscles  of  the  Forearm.— The  Flexor  carpiradialis  and 
Palmaris  longus  both  become  tendinous  about  the  middle  of  the  forearm. 
The  palmaris  longus  tendon  is  rather  longer  and  considerably  narrower 
than  that  of  the  flexor  carpi  radialis.  Both  muscles,  when  acting  with 
their  groups,  are  powerful  flexors  of  the  wrist  and  weak  flexors  of  the 
elbow.  When  the  flexor  carpi  radialis  acts  alone,  it  produces  flexion  and 
radial  deviation  at  the  wrist ;  when  it  acts  along  with  the  radial  extensors, 
radial  deviation  alone  takes  place. 

The  Flexor  digitorum  sublimis  (p.  84)  lies  deep  to  the  preceding  tendons 
and  partly  to  their  ulnar  side.  The  individual  tendons  arise  in  the  distal 
third  of  the  forearm,  and  pass  behind  the  transverse  carpal  (anterior  annular) 
ligament.  It  is  primarily  a  flexor  of  the  proximal  inter-phalangeal  joints, 
and  secondarily  a  flexor  of  the  metacarpo-phalangeal,  wrist,  and  elbow- 
joints. 

The  Flexor  carpi  ulnaris  (p.  67)  is  the  most  medially  placed  muscle  of  this 
group,  and  is  supplied  by  the  ulnar  nerve  (C.  8  and  T.  i).  When  acting 
with  its  group,  it  helps  to  flex  the  wrist  and  elbow  joints,  but,  when  acting 
with  the  extensor  carpi  ulnaris,  it  produces  ulnar  deviation  of  the  hand. 

Ulnar  Nerve.— The  course  of  the  Ulnar  Nerve  may  be 
indicated  by  drawing  a  line  from  the  medial  epicondyle  to 
the  lateral  margin  of  the  pisiform.  In  the  proximal  part  of  the 
forearm  the  nerve  is  almost  subcutaneous  and  may  be  rolled 
to  and  fro  against  the  ulna.  It  can  be  exposed  by  a  vertical 
incision  through  the  skin  and  fascia  behind  the  medial  epicondyle, 
and  is  found  in  contact  with  the  medial  side  of  the  elbow-joint. 

As  the  result  of  sudden  violent  flexion  of  the  elbow,  the  deep 
fascia  over  it  is  sometimes  torn  and  the  ulnar  nerve  slips  forwards 
round  the  medial  epicondyle.  This  dislocation  of  the  nerve 
may  require  operative  interference. 

After  supplying  the  joint,  the  ulnar  nerve  passes  between 
the  two  heads  of  the  flexor  carpi  ulnaris  and  almost  immediately 
gives  off  branches  to  supply  that  muscle  and  the  medial  part  of 


THE  SUPERIOR  EXTREMITY 


Triceps,  medial  head 

Median  nerve 
Brachialis 

Brachial  artery 
Ulnar  artery  -i 


Pronator  teres 
Flexor  carpi  radialis 

Palmaris  longus 
Flexor  carpi  ulnaris 


Ulnar  artery  and  nerve  - 
Transverse  carpal  ligament 


Biceps 


Lacertus  fibr 


Brachio-radialis 
Radial  artery 

Supinator 


Course  of  superficial 
division  of  radial  nerve 


Flexor  digitorum  sublimis 


Flexor  pollicis  longus 
Radial  artery 

Extensor  pollicis  brevis 
Abductor  pollicis  longus 


FIG.  25. — The  Anterior  Aspect  of  the  Forearm,  after  the  removal  of  all  the 
Structures  down  to  and  including  the  Deep  Fascia.  The  courses  taken 
by  the  nerves  and  arteries  are  indicated  by  the  interrupted  lines. 


THE  FOREARM  AND  WRIST  71 

the  flexor  digitorum  profundus.  It  runs  downwards  in  front 
of  the  latter  and  it  is  covered  by  the  flexor  carpi  ulnaris  in  the 
proximal  two-thirds  of  the  forearm.  Distally  it  again  becomes 
superficial,  lying  between  the  most  medial  tendon  of  the  flexor 
digitorum  sublimis,  on  the  radial  side,  and  the  tendon  of  the 
flexor  carpi  ulnaris,  on  the  ulnar  side.  At  the  junction  of  the 
proximal  and  middle  thirds  of  the  forearm,  it  becomes  associated 
with  the  ulnar  artery,  which  lies  close  to  its  lateral  side  through- 
out the  remainder  of  their  course  in  this  region. 

About  three  inches  from  the  pisiform,  the  ulnar  nerve  gives 
off  palmar  (p.  82)  and  dorsal  cutaneous  branches.  The  latter 
passes  backwards  below  the  styloid  process  of  the  ulna,  crosses 
the  medial  surface  of  the  os  triquetrum  (cuneiform)  and  gains 
the  dorsum  of  the  hand,  where  it  supplies  the  little  finger  and 
the  ulnar  side  of  the  ring  finger  (p.  72).  This  nerve  runs  some 
risk  of  being  cut  in  the  ulnar  incision  for  excision  of  the  wrist. 

Ulnar  Artery. — In  ligature  of  the  ulnar  artery  in  its 
distal  two-thirds,  the  incision  should  be  made  in  the  line  of  the 
ulnar  nerve.  In  the  middle  third,  the  flexor  carpi  ulnaris, 
which  overlies  it,  must  be  retracted  to  the  medial  side.  The 
course  of  the  proximal  third  is  indicated  by  a  line  drawn  from 
the  termination  of  the  brachial  artery  (p.  42)  to  the  point 
where  the  ulnar  artery  becomes  associated  with  the  ulnar  nerve. 
As  it  lies  deeply  under  cover  of  the  superficial  group  of  muscles 
and  is  crossed  close  to  its  origin  by  the  median  nerve,  the  artery 
is  rarely  tied  in  this  part  of  its  course. 

Branches. —  The  volar  and  dorsal  ulnar  recurrent  (p.  44) 
branches  arise  near  the  origin  of  the  ulnar  artery. 

The  Common  Interosseous  arises  more  distally  and  at  once 
divides  into  Volar  (Anterior)  and  Dorsal  branches.  The  former 
runs  distally  in  front  of  the  interosseous  membrane  and 
communicates  with  the  volar  carpal  arch.  It  pierces  the 
membrane  at  the  proximal  border  of  the  pronator  quadratus 
and  anastomoses  with  the  dorsal  carpal  arch  and  the  dorsal 
interosseous  artery.  The  latter  passes  backwards  proximal  to 
the  membrane  to  supply  the  extensor  muscles,  and  becomes 
associated  with  the  dorsal  interosseous  nerve. 

The  Superficial  (Radial)  Branch  of  the  Radial  (Musculo- 
Spiral)  Nerve  arises  in  front  of  the  lateral  epicondyle  under 
cover  of  the  brachio-radialis.  It  approaches  the  radial  artery 
and  lies  close  to  its  lateral  side  in  the  middle  third  of  the  forearm. 
About  3 1  inches  from  the  styloid  process  of  the  radius  the 

56 


72  THE  SUPERIOR  EXTREMITY 

nerve  leaves  the  artery  to  gain  the  dorsum  of  the  wrist  by 
passing  under  cover  of  the  brachio-radialis.  Here  it  is  joined 
by  communicating  twigs  from  the  dorsal  branch  of  the  musculo- 
cutaneous  and  from  the  dorsal  cutaneous  nerve  of  the  forearm 
(lower  external  cutaneous  branch  of  the  musculo-spiral  nerve). 
It  is  a  purely  sensory  nerve  and  terminates  on  the  back  of  the 
hand  by  supplying  the  skin  on  the  dorsal  aspects  of  the  thumb, 
index,  and  middle  fingers,  and  the  radial  side  of  the  ring  finger. 
Injuries  to  this  nerve  are  discussed  on  p.  102. 

The  dorsal  digital  nerves  do  not  reach  the  tips  of  the  fingers 
but  end  over  the  second  phalanges  ;  the  remainder  of  the  dorsal 
surface  is  supplied  by  the  digital  nerves  of  the  palm. 

Radial  Artery. — The  course  of  the  radial  artery  may  be 
indicated  by  a  line  drawn  from  the  termination  of  the  brachial 
artery  (p.  42)  to  the  navicular  tubercle.  In  the  proximal 
two-thirds  of  its  course  it  will  be  found  under  cover  of  the 
brachio-radialis.  In  the  proximal  third  it  lies  on  the  supinator, 
and  the  superficial  (radial)  branch  of  the  radial  (musculo-spiral) 
nerve  approaches  it  from  the  lateral  side.  In  the  middle  third  it 
lies  on  the  pronator  teres  and  the  radial  head  of  the  flexor 
digitorum  sublimis  while  the  nerve  is  close  to  its  lateral  side. 
The  distal  third  of  the  artery  is  subcutaneous  and  lies  upon  the 
flexor  pollicis  longus  and  the  radius  (Fig.  25). 

It  gives  off  the  radial  recurrent  (p.  43)  near  its  origin,  and 
the  superficial  volar  in  the  distal  part  of  the  forearm.  The 
latter  runs  through  or  over  the  short  muscles  of  the  thumb  to 
join  the  ulnar  artery  and  complete  the  superficial  palmar  arch 

(Fig.  30). 

If  the  radial  or  ulnar  artery  is  severed  in  more  than  one 
place,  all  the  cut  ends  must  be  tied,  as  the  muscular  branches 
of  the  radial,  ulnar,  and  volar  (anterior)  interosseous  arteries 
anastomose  very  freely  throughout  the  forearm.  When  the 
radial  artery  is  wounded  at  the  wrist,  both  ends  must  be  ligatured, 
owing  to  the  free  anastomosis  in  the  hand  (p.  86). 

The  Median  Nerve,  which  enters  the  forearm  between  the 
superficial  and  deep  heads  of  the  pronator  teres  (p.  68),  can 
be  indicated  by  a  line,  drawn  from  a  point  midway  between 
the  medial  epicondyle  and  the  biceps  tendon  to  a  point  at  the 
wrist,  slightly  to  the  medial  side  of  the  tendon  of  the  flexor 
carpi  radialis.  It  lies  between  the  superficial  and  deep  groups 
of  muscles,  and  is  bound  down  to  the  deep  surface  of  the  flexor 
digitorum  sublimis.  It  supplies  the  superficial  group  (p.  69), 


THE  FOREARM  AND  WRIST  73 

with  the  exception  of  the  flexor  carpi  ulnaris,  and  by  means  of 
its  volar  interosseous  branch  it  supplies  the  deep  muscles  of  the 
front  of  the  forearm.  Injuries  of  the  nerve  are  discussed  on 
p.  104. 

The  Deep  Group  of  Muscles  (Flexor  pollicis  longus,  Flexor  digitorum 
profundus,  and  Pronator  quadratus)  is  supplied  by  the  volar  interosseous  branch 
of  the  median  nerve  (C.  7,  8,.  and  T.  i),  with  the  exception  of  that  portion 
of  the  flexor  digitorum  profundus  destined  for  the  ring  and  little  fingers, 
which  is  supplied  by  the  ulnar  nerve  (C.  8  and  T.  i). 

The  Extensor  and  Supinator  Muscles.  —  The  Brachio  -  radialis, 
which  is  inserted  into  the  distal  part  of  the  lateral  surface  of  the  radius,  and 
the  Extensor  carpi  radialis  longus  are  both  supplied  by  the  radial  (musculo- 
spiral)  nerve  (C.  5  and  6,  C.  6  and  7,  respectively).  The  former  is  a  flexor 
of  the  forearm  ;  in  the  movement  of  supination  it  assists  until  the  mid-prone 
position  is  reached,  and  it  also  assists  pronation  from  the  supine  to  the  mid- 
prone  position. 

The  Supinator  (S.  brevis)  winds  round  the  posterior  aspect  of  the  proximal 
part  of  the  radius  and  is  thus  a  powerful  supinator.  It  is  supplied  by  the 
deep  branch  (posterior  interosseous)  of  the  radial  (musculo-spiral)  nerve  (C.  6). 

The  Ancon&us  covers  the  posterior  aspect  of  the  humero-radial  joint, 
and  is  supplied  by  a  branch  from  the  radial  (musculo-spiral)  nerve  (C.  7  and  8). 

The  Superficial  Group  of  Extensors  arises  from  the  distal  part  of  the 
anterior  aspect  of  the  lateral  epicondyle  of  the  humerus,  and  they  are  supplied 
by  the  dorsal  interosseous  nerve  (C.  6,  7,  and  8). 

This  group  comprises  the  Extensor  carpi  radialis  brevis  (p.  68),  the  Extensor 
digitorum  communis  (p.  92),  the  Extensor  digiti  quinti  proprius  (p.  92),  and 
the  Extensor  carpi  ulnaris  (pp.  69,  81). 

The  Deep  Group  of  Extensors  arises  from  the  dorsal  surfaces  of  the 
radius  and  ulna.  They  are  all  supplied  by  the  dorsal  interosseous  nerve 
(C.  6,  7,  and  8). 

The  Abductor  Pollicis  Longus  (extensor  ossis  metacarpi  pollicis)  (pp.  67,  75) 
is  inserted  into  the  base  of  the  metacarpal  bone  of  the  thumb.  It  extends 
the  thumb  at  the  carpo-metacarpal  joint. 

The  Extensor  Pollicis  Brevis  and  Longus  (pp.  68,  75)  are  inserted  into 
the  bases  -of  the  first  and  second  phalanges  respectively.  Primarily  they 
are  extensors,  but  they  also  aid  in  abduction  of  the  thumb. 

The  Extensor  Indicis  Proprius  (p.  92). 

The  Dorsal  Interosseous  Nerve  reaches  the  back  of  the 
forearm  by  winding  round  the  neck  of  the  radius,  in  the  substance 
of  the  supinator  (s.  brevis),  its  course  being  at  right  angles  to 
the  direction  of  the  muscle  fibres.  On  leaving  the  muscle 
(p.  67)  the  nerve  breaks  up  into  branches  which  are  distributed 
to  the  remaining  muscles  on  the  back  of  the  forearm. 

Surgical  Approach  to  the  Bones  of  the  Forearm.— 
The  Ulna  may  be  exposed  readily  in  any  part  of  its  extent  by 
incisions  along  its  subcutaneous  dorsal  border. 

The  Radius  may  be  exposed  by  incisions  along  the  line 
which  separates  the  radial  extensors  of  the  wrist  from  the 
extensor  digitorum  communis  (p.  67). 


Brachiulis 


Brachio-radial 


Extensor  carpi  radial 
long 


Extensor  carpi  radialis 
brevis 


Dorsal  interosseous  artery 
and  nerve 


Extensor  digitorum  communi 


Abductor  pollicis  longus 
and  extensor  pollicis  brevis  " 

Extensor  pollicis  longus  J 
Radius  ' 


Dorsal  carpal  ligament 

Extensor  carpi  radialis  brevis 

j 
Radial  artery  / 

First  dorsal  interosseou 


Triceps 


Head  of  radius 
Anconaeus 

Supinator 


Dorsal  border  of  ulna 


Aponeurosis  covering  flexor 
digitorum  profunclus 


Extensor  carpi  ulnaris 


Extensor  indicis  proprius 


Tendons  of  extensor  dig.  com. 

Extensor  digiti  quinti 
proprius 


FIG.  26. — The  Muscles  on  the  Dorsal  Aspect  of  the  Forearm.  The  course 
of  the  dorsal  interosseous  nerve,  where  it  is  not  exposed  to  view,  is 
indicated  by  the  interrupted  line.  The  extensor  digitorum  communis, 
digiti  quinti  proprius,  and  carpi  ulnaris,  have  been  divided  and  their 
proximal  parts  elevated. 

74 


THE  FOREARM  AND  WRIST  75 

(a)  Distal  Third. — At  its  proximal  end  the  incision  exposes 
the  extensor  pollicis  brevis   and  the  abductor  pollicis   longus 
as  they  cross  the  tendons  of  the  radial  extensors  of  the  wrist. 
The  extensor  digitorum  communis  is  exposed  on  the  ulnar  side 
of  the  incision  and  is   retracted  medially.     When  the  other 
muscles  and  tendons  mentioned  above  are  retracted  laterally,, 
the  distal  part  of  the  radius  is  exposed  where  it  is  devoid  of 
muscular  attachments.     In  tuberculous  osteo-myelitis  the  distal 
part  of  the  diaphysis  may  then  be  excised  by  dividing  it  proximal 
to  the  level  of  the  disease — the  periosteum  having  been  stripped 
off — and  by  wrenching  it  away  from  the  epiphyseal  cartilage, 
which  remains  attached  to  the  epiphysis.    The  capsule  of  the 
wrist  joint  is  uninjured  (Fig.  27). 

(b)  Middle  Third.  —  The   extensor   pollicis  brevis   and  the 
abductor  pollicis  longus  are  exposed  at  the  distal  end  of  the 
wound  and  are  retracted  distally  and  to  the  ulnar  side.    The 
radial  extensors  of  the  wrist  are  retracted  laterally,  and  the 
bone  is  exposed  between  the  origin  of  the  abductor  longus  and 
the  insertion  of  the  pronator  teres. 

(c)  Head  and  Proximal  Third. — When  the  extensor  digitorum 
communis  is  separated  from  the  radial  extensors  of  the  wrist  at 
this  level  the  supinator  is  exposed  and  must  be  divided  below 
and  parallel   to   the   dorsal  interosseous    nerve   (p.    73).     In 
subperiosteal  resection  of  this  part  of  the  radius  for  tuberculous 
osteo-myelitis,  the  bone  is  cut  through  distal  to  the  level  of 
the  disease  and  the  proximal  part  is  wrenched  away.     The 
cartilaginous  head  of  the  radius,  with  the  epiphysis  if  it  has 
developed,  is  wrenched  away  with  the  shaft,  as  it  is  attached 
only  to  the  synovial  membrane  of  the  elbow-joint  and  possesses 
no  special  ligamentous  connections  (Fig.  17).     In  this  resection, 
therefore,  the  cavity  of  the  elbow-joint  is  widely  opened. 

The  Distal  Radio-Ulnar  Joint.— The  ulna  is  excluded 
from  the  wrist-joint  by  a  triangular  fibro-cartilage — the  articular 
disc — which  is  attached  by  its  apex  to  the  base  of  the  styloid 
process  of  the  ulna  and  by  its  base  to  the  medial  margin  of  the 
distal  end  of  the  radius.  The  capsule  is  weak  and  loose,  to  permit 
of  pronation  and  supination,  and  the  synovial  membrane  bulges 
proximally  between  the  two  bones  beyond  the  level  of  the  distal 
epiphyseal  lines.  Occasionally  the  articular  disc  is  perforated, 
and  the  synovial  membrane  becomes  continuous  with  that  of 
the  wrist-joint. 

The  Radio-Carpal  Joint  or  Wrist- Joint.— The  proximal 


76  THE  SUPERIOR  EXTREMITY 

surface  of  the  proximal  row  of  carpal  bones  forms  a  surface 
which  is  convex  from  side  to  side  and  fits  into  a  correspondingly 
concave  surface  provided  by  the  carpal  aspect  of  the  radius 
and  the  articular  disc.  In  this  way  radial  and  ulnar  deviation 
of  the  hand  are  rendered  possible.  The  capsule  is  strengthened 
by: 

(i)  .The  Volar  and  (2)  Dorsal  Radio -Carpal  Ligaments, 
which  are  attached  to  the  margins  of  the  articular  surfaces  ; 
they  are  weak  bands.,  but  they  receive  additional  support  from 
the  flexor  and  extensor  tendons. 


FIG.  27. — Section  through  the  Carpus,  to  show  the  various  Joint  Cavities. 

Light  blue  =  articular  cartilage.  Green  =  periosteum. 

Striped  blue  =  ligaments.  Red  =  synovial  membrane. 

(3)  The   Radial   Collateral   (External   Lateral)   Ligament 
passes  from  the  tip  of  the  radial  styloid  to  the  lateral  surface  of 
the  navicular  and  is  crossed  by  the  second  part  of  the  radial 
artery. 

(4)  The  Ulnar  Collateral  (Internal)  Ligament  is  attached 
to  the  tip  of  the  ulnar  styloid  and  to  the  medial  side  of  the 
triquetrate  (cuneiform)  bone.     It  is  on  these  collateral  ligaments 
that  the  strength  of  the  joint  depends. 

The  Synovial  Membrane  lines  the  interior  of  the  capsule 
closely  ;  it  requires  no  special  description. 

Aspiration  of  the  joint  may  be  carried  out  immediately 


THE  FOREARM  AND  WRIST  77 

distal  to  the  tip  of  the  styloid  process  of  the  ulna  between  the 
extensor  and  flexor  carpi  ulnaris  tendons. 

Colles'  Fracture  occurs  from  a  fall  on  the  outstretched 
hand.  According  to  Chiene,  the  forearm  is  at  an  angle  of  less 
than  60°  to  the  horizontal  when  the  palm  of  the  hand  strikes  the 
ground.  The  line  of  force  cuts  through  the  distal  end  of  the 
radius  instead  of  passing  along  the  bone,  as  it  does  if  the  forearm 
is  at  an  angle  of  more  than  60°  to  the  ground  when  the  injury 
occurs.  Impaction  of  the  proximal  fragment  into  the  distal 
is  not  uncommon,  as  the  fracture  is  transverse  and  occurs 
through  the  spongy  tissue  of  the  distal  end  of  the  bone.  The 
line  of  force  drives  the  distal  fragment  backwards  and  tends 
to  thrust  it  proximally,  but  the  medial  edge  of  the  distal  end 
of  the  radius  is  attached  to  the  ulna  by  the  triangular  articular 
disc  (p.  75),  which  slips  backwards  over  the  head  of  the  latter 
bone.  The  styloid  process  of  the  radius  swings  round  the  arc 
of  a  circle  whose  radius  is  the  length  of  the  triangular  articular 
disc,  together  with  the  width  of  the  lower  end  of  the  radius. 
In  this  way  the  hand  is  deviated  to  the  radial  side,  and  the 
displacement  becomes  three-fold.  When  the  styloid  processes 
are  compared  (p.  66),  they  are  found  to  be  on  the  same  level  or 
the  radial  is  the  more  proximal. 

If  the  ulnar  styloid  also  is  fractured,  then  the  displacement 
is  backwards  and  upwards,  but  the  upward  displacement  is 
proportionately  greater  than  in  the  typical  Colles'  fracture. 
Smith's  Fracture  (reversed  Colles')  occurs  from  a  fall  on  the 
back  of  the  hand,  the  wrist  being  flexed.  The  line  of  force  cuts 
through  the  anterior  surface  of  the  distal  end  of  the  radius  and 
the  distal  fragment  is  thrust  forwards  and  proximally.  The 
hand  is  deviated  to  the  radial  side  as  in  Colles'  fracture  and 
for  the  same  reason. 

Ossification  of  the  Distal  Ends  of  the  Radius  and  Ulna. — 
Secondary  centres  for  the  distal  ends  of  the  Radius  and  Ulna 
appear  about  the  third  and  sixth  years,  respectively.  The 
distal  epiphyses  of  both  bones  include  the  styloid  processes 
and  the  articular  areas.  Growth  continues  longer  in  the  wrist 
region  than  it  does  at  the  elbow,  and  the  distal  epiphyses  do 
not  unite  till  between  twenty  and  twenty-four. 

Separation  of  the  distal  epiphyses  of  the  radius  and  ulna 
may  occur  between  the  ages  of  seven  and  twenty.  Owing  to 
the  line  of  attachment  of  the  capsule  of  the  wrist  (p.  76),  this 
injury  does  not  open  into  the  joint. 


y8  THE  SUPERIOR  EXTREMITY 

Owing  to  trauma  or  disease,  growth  may  cease  prematurely 
in  one  bone,  but  not  in  the  other.     As  the  healthy  bone  increases 


FIG.  28. — Carpus  of  an  Adolescent,  aged  sixteen.  The  centres  of  ossification 
for  all  the  carpal  bones  are  present,  but  those  for  the  os  multangulum  minus 
and  the  pisiform  are  obscured  by  the  os  multangulum  majus  and  the  os 
triquetrum,  respectively.  Observe  the  epiphysis  of  the  first  metacarpal  bone. 

in  length,  the  hand  gradually  becomes  deviated  to  the  affected 
side. 

Carpal  Joints. — With  the  exception  of  the  carpo-metacarpal 


THE  FOREARM  AND  WRIST  79 

joint  of  the  thumb  (p.  84)  and  the  joint  between  the  pisiform 
and  the  os  triquetrum  cuneiform),  all  the  inter-carpal,  carpo- 
metacarpal,  and  inter-metacarpal  joints  have  a  common  joint 
cavity  lined  with  a  single  synovial  membrane.  Their  volar 
(palmar)  and  dorsal  ligaments  are  continuous  with  the  corre- 
sponding ligaments  of  the  radio-carpal  joint  (p.  76). 

Ossification  of  the  Carpus. — At  the  end  of  the  first  year 
centres  appear  for  the  capitate  (os  magnum)  and  hamate 
(unciform)  bones.  These  are  followed  by  centres  for  the 
triquetrate  (cuneiform),  third  year ;  the  lunate  (semilunar), 
fifth  year ;  the  greater  multangular  (trapezium),  sixth  year ; 
the  navicular  (scaphoid),  sixth  year  ;  the  lesser  multangular 
(trapezoid),  seventh  year ;  and  the  pisiform  about  the  tenth 
year. 

Spread  of  Tuberculous  Disease  in  the  Wrist  Region.— 
The  capsules  of  the  distal  radio-ulnar  and  the  radio-carpal 
joints  do  not  encroach  on  the  diaphyses,  and,  consequently, 
tuberculous  disease  in  the  distal  ends  of  the  diaphyses  of  the 
radius  and  ulna  is  extra- cap sular .  When  it  breaks  out  under 
the  periosteum,  it  does  not  commonly  spread  distally  to  the 
joints,  unless  it  erupts  in  the  region  where  the  synovial  membrane 
of  the  distal  radio-ulnar  joint  pouches  proximally  between  the 
two  bones  (p.  75). 

The  carpal  bones  are  really  within  the  capsule  of  the  wrist- 
joint,  and  tuberculous  disease  arising  in  them  is  intra-capsular 
and  readily  reaches  the  joint  by  penetrating  the  articular 
cartilage.  If  the  disease  spreads  forwards  or  backwards, 
perforating  the  ligaments,  the  synovial  sheaths  of  the  tendons 
become  affected  ;  but  a  sympathetic  effusion  may  occur  into  the 
sheaths  while  the  disease  is  still  confined  to  the  joint,  and  it 
may  set  up  adhesions,  which  limit  the  movements  of  the  muscles 
concerned. 

Surgical  Approach  to  the  Wrist  -  Joint.— Pyogenic 
infections  of  the  wrist- joint  tend  to  point  on  the  dorsal  aspect, 
to  the  radial  or  ulnar  side  of  the  tendon  of  the  extensor  quinti 
digiti  proprius.  An  incision  immediately  to  the  ulnar  side  of 
the  tendon  of  the  extensor  carpi  ulnaris  affords  the  best  drainage 
when  the  forearm  is  subsequently  placed  in  the  mid -prone 
position. 

In  extensive  tuberculous  disease  the  Dorso-Ulnar  Incision 
(Kocher)  offers  the  best  approach,  and  little  damage  is  done  to 
the  tendons  if  the  subperiosteal  or  the  subcortical  method  is 


8o  THE  SUPERIOR  EXTREMITY 

adopted  in  elevating  the  dorsal  ligaments  of  the  wrist  and 
carpus.  Through  the  space  obtained  by  first  excising  the 
triquetrate  (cuneiform)  bone,  the  surgeon  is  able  to  divide  the 
hook  of  the  hamate.  This  process  and  the  pisiform  are  left 
behind  whenever  possible,  as  they  provide  attachments  for 
the  muscles  of  the  hypothenar  eminence  and  for  the  transverse 
carpal  (anterior  annular)  ligament.  The  remainder  of  the 
carpus  may  then  be  removed  piecemeal,  but,  if  practicable,  the 
greater  multangular  bone  (trapezium),  which  gives  attachment 
to  the  transverse  carpal  ligament,  is  left  behind.  Further,  the 
separate  carpo-metacarpal  joint  of  the  thumb,  which  is  not  neces- 
sarily affected  by  the  disease,  is  opened  into  when  the  greater 
multangular  bone  is  removed,  and  the  subsequent  movements 
of  the  thumb  (p.  84)  are  seriously  restricted.  After  removal 
of  the  carpus,  the  extremities  of  the  radius,  ulna,  and  metacarpals 
may  be  dislocated  into  the  wound  and  resected,  if  necessary. 
The  wrist  is  subsequently  dorsi-flexed,  lest  the  powerful  flexors 
should  overstretch  the  weaker  extensor  muscles. 

In  Dislocation  of  the  Capitate  Bone  (Os  Magnum)  the  head  of  the 
bone  projects  dorsally,  opposite  the  base  of  the  third  metacarpal,  and  the 
deformity  is  increased  on  flexion  of  the  hand. 

The  Lunate  (Semilunar)  Bone  may  be  dislocated  forwards  by 
forcible  extension  of  the  hand.  In  this  case  the  ulnar  nerve  may  be  injured. 

The  Navicular  Bone  may  be  fractured  at  its  narrowest  part  when  it 
is  driven  against  the  distal  end  of  the  radius  by  the  rounded  head  of  the  os 
capitatum  (os  magnum).  Forward  displacement  of  the  greater  and  lesser 
multangular  bones  (trapezium  and  trapezoid)  sometimes  accompanies  this 
injury. 


THE  HAND. 

Bony  Landmarks.— The  base  of  the  First  Metacarpal  is 
readily  felt  in  the  angle  between  the  tendons  of  the  extensor 
pollicis  brevis  and  longus,  and  the  dorsal  surface  of  its  shaft 
can  also  be  felt,  though  it  is  somewhat  obscured  by  the  extensor 
tendons. 

In  Bennetfs  Fracture,  which  passes  obliquely  through  the 
base  of  the  first  metacarpal,  the  large,  distal  fragment  is  drawn 
proximally  and  slightly  backwards  by  the  combined  action  of 
the  flexors  and  extensors  of  the  thumb.  The  small,  proximal 
fragment,  which  generally  includes  a  part  of  the  ulnar  side  of 
the  shaft,  suffers  little  displacement.  Abnormal  movement 


THE  HAND  81 

and  crepitus  are  difficult  to  obtain,  as  it  is  not  easy  to  fix  the 
proximal  fragment,  owing  to  its  small  size.  This  fracture  was 
difficult  to  recognise  before  the  introduction  of  X-rays  and  was 
frequently  mistaken  for  a  sprain  of  the  carpo-metacarpal  joint. 

The  whole  of  the  radial  border  and  most  of  the  dorsal  surface 
of  the  Second  Metacarpal  can  be  readily  examined  ;  its  enlarged 
base  forms  a  prominence  on  the  back  of  the  hand. 

The  dorsal  surfaces  of  the  Third,  Fourth,  and  Fifth 
Metacarpals  are  obscured  by  the  extensor  tendons,  but  the 
Styloid  Process  on  the  base  of  the  third  can  be  felt  about  two 
fingers'  breadths  directly  distal  to  the  dorsal  radial  tubercle 
(p.  66) ;  the  tendon  of  the  extensor  carpi  radialis  brevis  is 
attached  to  it.  On  the  ulnar  border  of  the  hand,  the  tendon 
of  the  extensor  carpi  ulnaris  can  be  traced  to  its  insertion  into 
the  base  of  the  fifth  metacarpal. 

Fractures  of  the  metacarpal  bones,  when  produced  by  direct 
violence,  are  transverse  and  show  little  displacement.  When 
they  follow  indirect  violence,  they  tend  to  be  oblique,  and  the 
distal  fragment  is  generally  displaced  proximally  and  backwards, 
causing  a  slight  shortening  of  the  corresponding  finger. 

The  prominences  of  the  knuckles  are  produced  by  the  heads 
of  the  metacarpal  bones.  The  dorsal  groove  corresponding  to 
each  metacarpo-phalangeal  joint  lies  one-third  of  an  inch  distal 
to  the  head  of  each  metacarpal.  On  the  palmar  aspect  the 
joint  corresponds  to  the  lower  skin  crease  of  the  palm  and  lies 
three-quarters  of  an  inch  from  the  edge  of  the  web  of  the  fingers. 

The  dorsal  line  of  each  proximal  inter-phalangeal  joint  lies 
one-sixth  of  an  inch  distal  to  the  prominence  of  the  head  of  the 
first  phalanx,  and  corresponds,  on  the  palmar  aspect,  to  the 
most  proximal  skin  crease  at  the  joint.  The  dorsal  line  of 
each  distal  inter-phalangeal  joint  lies  one-twelfth  of  an  inch 
distal  to  the  prominence  formed  by  the  head  of  the  second 
phalanx  and  corresponds,  on  the  palmar  surface,  to  the  most 
distal  skin  crease  at  the  joint. 

The  Superficial  Fascia  of  the  palm  is  rendered  extremely 
tough  by  the  presence  of  numerous  fibrous  septa,  which  connect 
the  deep  surface  of  the  skin  to  the  palmar  aponeurosis  (deep 
palmar  fascia).  On  this  account  pus  does  not  accumulate  in 
any  quantity  in  this  situation,  but  makes  its  way  through  the 
cutis  vera  and  collects  under  the  epidermis  as  a  purulent  blister. 
Over  the  terminal  phalanges  the  superficial  fascia  forms  fatty 
pads,  which  are  connected  to  the  periosteum  by  fibrous  septa. 


82  THE  SUPERIOR  EXTREMITY 

Superficial  septic  infection  in  this  region,  unless  freely  incised 
at  an  early  stage,  is  apt  to  spread  along  the  septa  and  cause 
suppurative  periostitis.  Ultimately,  necrosis  of  the  phalanx 
occurs  although  sometimes  the  base  of  the  bone,  with  the 
attachment  of  the  flexor  profundus  tendon,  is  left  behind. 

On  the  dor  sum  of  the  hand  the  superficial  fascia  is  thin  and 
membranous.  It  contains  most  of  the  lymph  vessels  of  the 
fingers  and  an  irregular  venous  network,  which  gives  rise  to  the 
basilic,  median,  and  cephalic  veins. 

Superficial  Vessels  and  Nerves. — The  skin  of  the  palm  is 
supplied,  as  far  as  the  heads  of  the  metacarpals,  by  palmar 
cutaneous  branches  from  the  ulnar,  median,  and  radial  nerves. 
The  digital  vessels  (p.  86)  and  the  digital  nerves  (p.  86),  which 
lie  anterior  to  them,  are  situated  in  the  superficial  fascia  on  the 
sides  of  the  fingers,  nearer  the  palmar  than  the  dorsal  surface. 

The  skin  on  the  dorsum  is  supplied  by  the  terminal  part  of 
the  superficial  (radial)  branch  of  the  radial  (musculo-spiral)  nerve 
(p.  71)  and  by  the  dorsal  cutaneous  branch  of  the  ulnar  (p.  71). 

Lymph  Vessels. — All  the  superficial  lymph  vessels  of  the 
fingers  and  palm,  save  those  of  the  proximal  part  which  run  up 
the  front  of  the  forearm,  pass  to  the  dorsum  of  the  hand,  and 
become  associated  with  the  superficial  veins.  They  are  joined 
by  the  deep  lymph  vessels  of  the  palm,  which  reach  the  dorsum 
by  passing  across  the  distal  border  of  the  transverse  head  of 
the  adductor  pollicis.  This  arrangement  explains  the  frequency 
with  which  oedema  or  even  metastatic  abscesses  may  occur  on  the 
dorsum  of  the  hand,  following  septic  infection  of  the  fingers  or 
palm. 

Deep  Fascia. — The  deep  fascia  of  the  forearm  fuses  below 
with  the  palmar  surface  of  the  Transverse  Carpal  (Anterior 
Annular)  Ligament,  which  is  a  strong  fibrous  band,  situated 
in  the  proximal  part  of  the  hand.  It  provides  a  retentive 
apparatus  for  the  flexor  tendons,  and  is  attached  to  the  pisiform, 
and  the  hook  of  the  hamate  (unciform)  on  the  ulnar  side,  and 
to  the  navicular  tubercle  and  the  ridge  of  the  greater  multangular 
bone  (trapezium)  on  the  radial  side.  A  short  band  of  fibres 
passes  from  the  pisiform  to  fuse  with  the  palmar  surface  of  the 
ligament  and,  under  cover  of  it,  the  ulnar  nerve  and  artery  are 
continued  into  the  palm. 

The  deep  fascia  of  the  palm,  which  is  termed  the  palmar 
aponeurosis,  consists  of  a  strong  central  portion,  and  two  weak 
expansions  which  cover  the  muscles  of  the  thenar  and  hypothenar 


THE  HAND 


eminences  respectively.  The  central  portion  is  exceedingly 
dense,  and  prevents  the  forward  spread  of  pus  or  blood. 
Proximally,  it  blends  with  the  transverse  carpal  ligament ; 
distally,  it  widens  out  and  breaks  up  into  four  slips,  which  become 
continuous  with  the  fibrous  digital  sheaths. 

On  the  palmar  aspect  of  the  fingers,,  the  deep  fascia  is 
attached  to  the  borders  of  the  phalanges  and  to  the  inter- 
phalangeal  ligaments.  On  the  terminal  phalanx  it  is  attached 
to  the  palmar  surface  of  the  bone  immediately  beyond  the 
insertion  of  the  tendon  of  the  flexor  digitorum  profundus.  In 
this  way  it  forms  a  fibrous  sheath  for  the  flexor  tendons,  which 
lie  in  an  osteo-fascial  canal  on  the  front  of  the  fingers.  The 


Vinculum  breve 

Vinculum  longum  ! 

Insertion  of  flexor  digitorum  sublimis  tendon  | 

Fibrous  sheath  | 

Flexor  digitorum  sublimis  tendon   | 

Flexor  digitorum  profundus  tendon 

FIG.  29. — Longitudinal  Section  through  the  Third  Finger,  to  show  the 
arrangement  of  the  Fibrous  and  Synovial  Sheaths. 

Light  blue  =  articular  cartilage.  Green  =  periosteum. 

Dark  blue  =  ligaments.  Red  =  synovial  membrane. 

sheath  is  thinner  and  weaker  opposite  the  inter-phalangeal 
joints,  to  allow  of  free  flexion  (Fig.  29). 

In  the  early  stages  of  Dupuytren's  Contraction  the 
metacarpo-phalangeal  joints,  generally  of  the  ring  and  little 
finger,  become  flexed,  owing  to  an  interstitial  fibrosis  of  the 
medial  part  of  the  central  portion  of  the  palmar  aponeurosis. 
Later,  the  inter-phalangeal  joints  also  become  flexed,  as  the 
fibrosis  attacks  the  weak  areas  which  are  present  in  the  fibrous 
digital  sheaths  opposite  the  joints. 

In  Congenital  Contraction  of  the  Fingers,  which  also 
affects  the  ring  and  little  fingers,  the  metacarpo-phalangeal 
joints  are  hyperextended  and  the  inter-phalangeal  joints  are 
flexed.  This  contraction,  therefore,  is  not  caused  by  the  action 
of  the  aponeurosis,  but  is  suggestive  of  some  functional  in- 
capacity of  the  lumbricals  supplied  by  the  ulnar  nerve  (p.  84). 

Qa 


84  THE  SUPERIOR  EXTREMITY 

The  Hypothenar  Eminence  is  produced  by  the  abductor,  the  opponens 
and  the  flexor  brevis  digiti  quinti.  These  muscles  are  all  supplied  by  the  deep 
branch  of  the  ulnar  nerve  (C.  8  and  T.  i),  and  their  actions  are  sufficiently 
described  by  their  names.  When  pus  forms  in  the  hypothenar  eminence,  it 
is  localised  to  that  area,  as  it  is  shut  off  from  the  central  portion  of  the  palm 
by  &  fibrous  septum,  which  passes  backwards  from  the  ulnar  side  of  the  central 
portion  of  the  palmar  aponeurosis.  In  these  cases  the  incision  is  made  over 
the  ulnar  side  of  the  fifth  metacarpal  bone,  dorsal  to  the  pisiform.  The 
nerves  of  supply,  which  enter  the  muscles  close  to  the  pisiform,  are  not  inter- 
fered with  by  this  incision,  and  no  damage  is  done  to  the  first  digital  branches 
of  the  superficial  volar  arch  and  ulnar  nerve,  which  run  distally,  in  front  of 
the  flexor  digiti  quinti  brevis,  to  supply  the  ulnar  side  of  the  little  finger. 

The  Thenar  Eminence  is  formed  by  the  abductor  pollicis,  the  flexor 
pollicis  brevis,  and  the  opponens  pollicis,  which  lies  deep  to  the  preceding 
two  muscles.  These  three  muscles  lie  to  the  radial  side  of  the  tendon  of  the 
flexor  pollicis  longus,  and  are  all  supplied  by  the  median  nerve  (C.  8  and  T.  i). 
They  are  shut  off  from  the  central  space  of  the  palm  by  a  fibrous  septum, 
which  passes  backwards  from  the  radial  border  of  the  central  portion  of  the 
palmar  aponeurosis.  When  pus  forms  amongst  these  muscles,  it  is  very 
definitely  localised,  and  shows  no  tendency  to  spread  backwards  or  medially. 
The  incision  lies  over  the  distal  part  of  the  first  metacarpal  and  on  the  radial 
side  of  the  eminence,  thus  avoiding  the  nerves  of  supply,  which  enter  the 
muscles  at  their  carpal  ends,  and  the  digital  nerve  to  the  radial  side  of  the 
thumb  (Fig.  30). 

Movements  of  the  Thumb. — Flexion  and  extension  are  the  only  move- 
ments which  occur  at  the  metacarpo-phalangeal  and  inter-phalangeal  joints 
of  the  thumb.  The  additional  movements  of  abduction,  adduction,  and 
opposition  all  take  place  at  the  carpo-metacarpal  joint,  where  the  os  mult- 
angulum  majus  (trapezium)  articulates  with  the  first  metacarpal  bone. 
This  joint  possesses  a  special  synovial  membrane,  distinct  from  the  synovial 
membrane  of  the  neighbouring  joints.  Abduction  and  adduction  occur  in 
an  antero-posterior  plane,  and  the  former  movement  must  not  be  confused 
with  true  extension,  which  occurs  in  a  medio-lateral  plane. 

The  Central  Portion  of  the  Palm.— The  tendons  of 
the  flexor  digitorum  sublimis  and  profundus  lie  behind  the 
central  portion  of  the  palmar  aponeurosis  before  they  enter 
the  fibrous  digital  sheaths.  Opposite  the  first  phalanx  each 
sublimis  tendon  splits,  to  allow  the  corresponding  profundus 
tendon  to  pass  on  to  be  inserted  into  the  base  of  the  distal 
phalanx.  Under  cover  of  the  profundus  tendon  the  two  slips 
of  the  sublimis  tendon  receive  attachment  to  the  borders  of  the 
second  phalanx. 

The  four  Lumbrical  Muscles  arise  from  the  tendons  of  the 
flexor  digitorum  profundus  in  the  palm,  and  are  inserted  into 
the  radial  side  of  the  dorsal  extensor  expansion  (p.  92)  and 
the  adjoining  part  of  the  first  phalanx  of  the  medial  four  digits. 
They  flex  the  fingers  at  the  metacarpo-phalangeal  joints,  but 
extend  them  at  the  inter-phalangeal  joints,  through  the  medium 
of  the  extensor  expansion.  The  lumbricals  of  the  little  and 
ring  fingers  are  supplied  by  the  deep  branch  of  the  ulnar  nerve 


THE  HAND  85 

(C.  8  and  T.  i) ;  those  of  the  middle  and  index  fingers,  by  the 
median  nerve  (C.  8  and  T.  i). 

The  Ulnar  Nerve  divides  into  superficial  and  deep  branches 
opposite  the  hook  of  the  hamate  bone.  The  former  supplies 
digital  branches  to  the  little  finger  and  to  the  ulnar  side  of  the 


Volar  radial  a.  of  index   '-,, 
Digital  branch  of  median  n. 

A.  princeps  pollicis 
Branch  to  muscles  of  thuml 


4; —  Digital  arteries 


Superficial  volar 
-    arch 

'    Deep  volar  arch 
"    and  deep  branch 

of  ulnar  nerve 

Ulnar  artery 
Ulnar  nerve 


A.  superficialis  \O\BS 

Os  multangulum  majus    -^ 

Radial  artery  ~^|j 
Median  ne 


FIG.  30. — The  Positions  of  the  Vessels  and  Nerves  Relative  to  the  Bones 
of  the  Hand  and  Wrist. 

ring  finger.  The  latter  supplies  the  muscles  of  the  hypothenar 
eminence  and  runs  transversely  across  the  palm  to  end  in  the 
oblique  head  of  the  adductor  pollicis.  In  its  course  it  accom- 
panies the  deep  volar  arch  (p.  92),  and  lies  behind  the 
flexor  tendons  and  in  front  of  the  interossei  and  the  proximal 
ends  of  the  middle  three  metacarpals.  In  addition  to  the 
muscles  already  mentioned,  it  supplies  all  the  interossei,  the 

6ft 


86  THE  SUPERIOR  EXTREMITY 

transverse  head  of  the  adductor  pollicis,  and  the  medial  two 
lumbricals. 

The  Median  Nerve  enters  the  palm  behind  the  transverse 
carpal  (anterior  annular)  ligament.  At  the  lower  border  of 
the  ligament  it  breaks  up  into  lateral  and  medial  divisions. 
The  lateral  division  at  once  supplies  the  thenar  muscles 
(p.  84)  and  gives  off  digital  branches  to  supply  both  sides  of 
the  thumb  and  the  radial  side  of  the  index  ringer.  The  medial 
division  gives  off  two  branches,  which  run  to  the  second  and 
third  clefts  to  supply  the  adjacent  sides  of  the  index,  middle,  and 
ring  fingers,  and  twigs  to  their  dorsal  apects  (p.  72).  The 
digital  branches  of  the  radial  side  of  the  index  finger  and  the 
second  cleft  supply  the  first  and  second  lumbricals  respectively. 

The  Superficial  Volar  (Palmar)  Arch  is  the  continuation  of 
the  ulnar  artery  into  the  palm.  It  runs  obliquely,  distally,  and 
laterally  across  the  hook  of  the  hamate  to  reach  the  mid-point 
between  the  base  of  the  middle  finger  and  the  distal  skin  crease 
at  the  wrist.  The  mode  of  termination  of  the  arch  is  very 
variable,  but  it  is  always  joined  by  a  branch  from  the  radial 
artery  (superficialis  volse,  princeps  pollicis  or  radialis  indicis), 
and  the  anastomosis  is  so  free  that  in  wounds  of  the  arch  both 
the  cut  ends  require  to  be  tied.  The  artery  lies  immediately 
under  cover  of  the  central  part  of  the  palmar  aponeurosis,  and 
it  crosses  in  front  of  the  flexor  tendons  and  their  sheaths  and 
the  digital  branches  of  the  median  nerve. 

It  gives  off  four  Digital  Branches.  The  first  supplies  the 
ulnar  side  of  the  little  finger  (p.  84) ;  the  second  passes  to  the 
fourth  cleft,  and  lies  to  the  ulnar  side  of  the  fourth  metacarpal 
bone  ;  the  third  passes  to  the  third  cleft  and  lies  to  the  radial 
side  of  the  same  bone ;  the  fourth  crosses  the  third  metacarpal 
bone  to  gain  the  second  cleft.  An  incision  can  therefore  be  made 
over  the  distal  part  of  the  fourth  metacarpal  bone,  without  injuring 
the  superficial  volar  arch  or  any  of  its  digital  branches  (Fig.  30). 

Synovial  Sheaths  of  the  Flexor  Tendons. — As  the  flexor 
tendons  pass  into  the  palm,  they  are  invested  with  synovial 
sheaths,  which  are  arranged  in  a  somewhat  complicated  manner. 

The  tendon  of  the  flexor  pollicis  longus  has  a  separate  sheath, 
which  extends  distally  as  far  as  its  insertion  and  proximally  for 
an  inch  or  more  beyond  the  transverse  carpal  ligament.  It 
consists  of  a  "  visceral "  layer,  closely  applied  to  the  tendon, 
and  a  parietal  layer,  which  lines  the  walls  of  the  space  occupied 
by  the  tendon.  At  both  extremities  of  the  sheath  the  parietal 


THE  HAND  87 

layer  is  reflected  on  to  the  tendon  to  become  continuous  with 
the  "  visceral "  layer,,  so  that  the  two  enclose  an  elongated 
bursal  space. 

In  the  fcetus  the  tendon  is  invaginated  into  the  synovial 
bursa  from  behind,  and  at  first  possesses  a  "  mesentery " 
throughout  its  whole  extent  in  the  sheath.  This  complete 
"  mesentery  "  breaks  down  in  places,  but  it  persists  as  the  liga- 
mentum  breve,  a  triangular  fold  attaching  the  terminal  part  of 
the  tendon  to  the  floor  of  its  canal,  and  as  the  ligamenta  longa, 
which  connect  it  to  the  floor  in  two  or  three  places  at  a  more 
proximal  level  (Fig.  29). 

The  tendons  of  the  flexor  digitorum  sublimis  and  profundus 

Transverse  carpal  ligament  Tendons  of  flexor  digitorum  sublimis 

Median  nerve 
Tendon  of  flexor  { 

pollicis  longi 

Tendon  of  flexor 
carpi  radial 


Tendons  of  flexor  digitorum  profundus 

FIG.  31.— Diagram  of  a  Transverse  Section  through  the  Carpus,  to  show  the 
arrangement  of  the  Synovial  Sheaths. 

are  provided  with  a  single  large  sheath  (the  common  palmar 
sheath),  which  extends  proximally  as  far  as  that  of  the  flexor 
pollicis  longus.  Its  distal  limit  is  oblique,  reaching  a  more 
distal  level  on  the  ulnar  than  on  the  radial  side.  The  most 
medial  part  of  the  sheath  is  carried  distally  on  the  tendons  of 
the  little  finger  to  their  insertions  (Fig.  32). 

Figure  31  represents  a  transverse  section  through  the  wrist 
at  the  level  of  the  transverse  carpal  ligament.  From  this  it 
will  be  seen  that  the  tendons  have  been  invaginated  into  the 
common  palmar  sheath  on  its  radial  side,  and  have  formed  three 
pouches — one  in  front  of  the  sublimis,  pre-tendinous  pouch  ;  one 
between  the  two  groups  of  tendons,  inter -tendinous  pouch  ;  and 
a  third,  between  the  profundus  and  the  floor  of  the  carpal  tunnel, 

6c 


88  THE  SUPERIOR  EXTREMITY 

retro-tendinous  pouch.  The  open  space  at  the  ulnar  side  of  the 
sheath,  with  which  all  three  pouches  communicate  freely,  is 
termed  the  ulnar  bursa. 

The  median  nerve  is  situated  between  the  sheath  of  the 
flexor  pollicis  longus  and  the  common  palmar  sheath. 

Digital  Synovial  Sheaths  invest  the  flexor  tendons  as  they 
lie  in  their  osteo-fascial  canals  on  the  front  of  the  fingers.  They 
extend  distally  as  far  as  the  insertion  of  the  profundus  tendons, 
and  proximally  for  half  an  inch  beyond  the  metacarpo-phalangeal 
joints.  Ligamenta  longa  and  brevia  are  present  as  in  the  case 
of  the  flexor  pollicis  longus  (Fig.  29).  The  digital  synovial 
sheath  of  the  little  finger  is  directly  continuous  with  the  common 
palmar  sheath,  but  the  others  are  definitely  closed  at  their 
proximal  ends. 

The  following  variations  are  described  by  Poirier. 

1.  The  index  tendon  of  the  profundus  possesses  a  separate  palmar  sheath, 
80  per  cent. 

2.  The  flexor  pollicis  longus  sheath  communicates  freely  at  its  proximal 
part  with  the  common  sheath,  50  per  cent. 

3.  The  digital  sheath  of  the  little  finger  fails  to  communicate  with  the 
common  sheath,  35  per  cent. 

4.  The  flexor  pollicis  longus  sheath  is  in  two  separate  parts,  a  digital  and 
a  carpal,  5  per  cent. 

Pus  in  the  Common  Palmar  Sheath.  —  The  common 
palmar  sheath  may  be  infected  primarily  by  punctured  wounds 
of  the  palm  or  it  may  be  involved  secondarily,  following  a  septic 
infection  either  of  the  digital  synovial  sheath  of  the  little  finger 
(Fig.  32)  or  of  the  middle  palmar  space  (p.  90).  Incisions  into 
the  -proximal  part  of  the  sheath  are  made  in  the  line  of  the  ring 
finger,  and  are  limited  distally  by  the  distal  skin  crease  at  the 
wrist.  In  this  way  no  damage  is  done  to  the  median  nerve 
which  lies  to  the  radial  side  of  the  incision  or  to  the  ulnar  nerve 
and  artery,  which  lie  to  its  medial  side.  Incisions  into  the  distal 
part  of  the  sheath  are  made  in  the  same  line,  but  are  limited 
proximally  by  the  distal  border  of  the  transverse  carpal  ligament 
and  distally  by  the  superficial  palmar  arch.  If  the  pus  ruptures 
the  common  palmar  sheath  and  extends  into  the  forearm,  it 
may  be  evacuated  by  incisions  along  the  same  line  (Fig.  32). 

Compound  Palmar  Ganglion. — This  condition  is  a  tuber- 
culous synovitis  affecting  the  common  palmar  sheath.  It  gives 
rise  to  a  dumb-bell-shaped  swelling,  which  extends  from  the 
distal  part  of  the  forearm  into  the  palm,  the  constriction  being 
due  to  the  transverse  carpal  ligament.  Should  a  cold  abscess 


THE  HAND  89 

arise,  the  common  palmar  sheath  may  require  to  be  excised, 


Digital  synovial  sheath 


Synovial  sheath  of 
flex.  poll.  long. 


Ridge  on  os  multangulum  majus  • 

Transverse  carpal  ligament , 

Tuberosity  of  naviculai 


Common 
"  palmar  sheath 


Pisiform 


FIG.  32. — The  Synovial  Sheaths  of  the  Wrist  and  Hand.      The  positions  of 
various  incisions  for  the  evacuation  of  pus  are  also  shown. 

i  and  2.  Incisions  into  the  common  palmar  sheath,  placed  between  the  median  and 
ulnar  nerves. 

3.  Incision  uniting  i  and  2. 

4.  Incision  into  the  proximal  part  of  the  sheath  of  flexor  pollicis  longus.     It  is  placed 
between  the  radial  artery  and  the  median  nerve. 

5.  Incision  into  the  distal  part  of  the  sheath  of  flexor  pollicis  longus. 

6.  Incision  into  the  thenar  space. 

7.  Incision  over  terminal  phalanx. 

8.  9  and  10.  Incisions  into  the  digital  sheaths.     They  lie  opposite  the  shafts  of  the 
phalanges. 

though  the  operation  usually  results  in  some  damage  to  the 
median  and  ulnar  nerves. 

Deep  Muscles  of  the  Palm. — The  adductor  pollicis  possesses  a  transverse 


9o  THE  SUPERIOR  EXTREMITY 

and  an  oblique  head,  which  are  both  supplied  by  the  deep  branch  of  the  ulnar 
nerve  (C.  8).  It  forms  a  triangular  sheet  of  muscle,  with  its  base  attached  to  the 
third  metacarpal  bone  and  its  apex  to  the  base  of  the  first  phalanx  of  the  thumb. 
In  the  interval  between  the  two  heads  the  radial  artery  enters  the  palm. 

The  three  volar  {palmar)  interossei,  which  arise  from  the  metacarpal  bones 
of  the  fingers  on  which  they  act,  adduct  the  little,  ring,  and  index  fingers  to  the 
middle  line  of  the  hand.  The  four  dorsal  interossei  abduct  the  ring,  middle,  and 
index  fingers  from  the  same  line.  Both  groups  are  supplied  by  the  deep  branch 
of  the  ulnar  nerve  (C.  8  and  T.  i),  and,  in  addition  to  the  above  actions,  they 
help  to  flex  the  fingers  at  the  metacarpo-phalangeal  joints  and  to  extend  them 
at  the  inter-phalangeal  joints,  the  latter  by  virtue  of  their  partial  insertion 
into  the  dorsal  extensor  expansion. 

Fascial  Spaces  of  the  Palm.  —  Behind  the  flexor  tendons  and  the 
lumbrical  muscles,  there  exists  a  large  fascial  space,  which  is  subdivided  into 
a  Middle  Palmar  and  a  Thenar  Space  by  a  septum  of  fibrous  tissue  attached 
to  the  third  metacarpal  bone  (Kanavel).  This  septum  is  weakened  at  its 
proximal  end,  but  it  is  usually  strong  enough  to  prevent  the  spread  of  pus 
from  the  one  space  to  the  other. 

The  Middle  Palmar  Space  lies  to  the  radial  side  of  the  hypothenar 
eminence,  from  which  it  is  completely  separated  by  a  fascial  septum  (p.  84). 
It  is  bounded  behind  by  the  strong  fascia  which  covers  the  interosseous 
muscles  in  the  third  and  fourth  spaces,  and  in  front  by  the  tendons  of  the 
middle,  ring,  and  little  fingers  with  their  lumbrical  muscles.  This  fascial 
space  may  be  primarily  infected  by  punctured  wounds  or  by  compound 
fractures  of  the  third,  fourth,  and  fifth  metacarpals.  It  can  be  involved 
secondarily  to  superficial  infections  of  the  same  fingers,  the  spread  occurring 
along  the  sheath  of  the  lumbrical  muscle ;  or  it  may  be  involved  by  direct 
spread  from  the  digital  synovial  sheaths  of  the  third  and  fourth  fingers, 
the  pus  rupturing  through  the  closed  proximal  end  of  the  sheath.  If  not 
evacuated,  pus  in  the  middle  palmar  space  may  spread  distally  to  point  at 
the  web  of  the  fingers ;  or  it  may  spread  proximally  behind  the  tendons 
into  the  forearm ;  or,  in  neglected  cases,  it  may  pass  backwards  between 
the  metacarpal  bones  and  infect  the  dorsal  subaponeurotic  space  (p.  91). 
Incisions  into  the  space  are  made  over  the  distal  half  of  the  fourth  metacarpal 
bone  (p.  86),  and  the  tendons  of  the  ring  finger  are  exposed  at  a  point  where 
they  have  no  synovial  sheath.  In  this  way  the  middle  palmar  space  can  be 
reached  without  opening  into  the  common  palmar  sheath,  which  is  not 
necessarily  infected. 

The  Thenar  space  lies  between  the  middle  palmar  space  and  the  tendon 
of  the  flexor  pollicis  longus.  It  is  bounded  behind  by  the  adductor  of  the 
thumb  and  in  front  by  the  tendons  of  the  index  finger  and  the  first  lumbrical 
muscle.  Primary  infections  of  this  space  may  occur  through  punctured 
wounds,  and,  very  rarely,  through  compound  fracture  of  the  second  meta- 
carpal, which  is  separated  from  it  by  the  adductor  muscle  of  the  thumb. 
Septic  infections  of  the  index  finger  may  involve  the  space  secondarily, 
following  the  same  routes  as  have  been  described  above  in  connection  with 
the  middle  palmar  space.  Pus  in  the  thenar  space  may  spread  backwards 
between  the  two  heads  of  the  adductor  muscle,  or  over  the  distal  border  of 
the  transverse  head  to  point  on  the  dorsal  surface  of  the  web  of  the  thumb. 
It  may  also  pass  proximally  into  the  forearm  or  distally  to  the  interval  be- 
tween the  index  and  middle  fingers.  Incisions  into  the  thenar  space  are  made 
over  the  distal  half  of  the  second  metacarpal  (Fig.  32),  and  "  through  and 
through  "  drainage  may  be  obtained  in  the  space  between  the  first  and 
second  metacarpal  bones. 

The    Dorsal   Carpal   (Posterior   Annular)   Ligament  is  a 


THE  HAND  91 

thickened  portion  of  the  deep  fascia  on  the  back  of  the  wrist. 
It  is  attached  to  the  volar  (anterior)  border  and  styloid  process 
of  the  radius,  and  it  passes  obliquely  across  the  dorsum  of  the 
wrist,  to  be  attached  to  the  styloid  process  of  the  ulna  and  the 
medial  border  of  the  carpus.  Septa  unite  its  deep  surface  to 
the  dorsal  aspect  of  the  radius,  and  form  complete  osteo-fascial 
tunnels  for  the  extensor  tendons. 

Synovial  Sheaths  of  Extensor  Tendons.— Synovial  sheaths 
invest  the  extensor  tendons  as  they  lie  under  cover  of  the  dorsal 
carpal  ligament.  They  extend  for  a  short  distance  proximal 
to  the  ligament  and  distally  for  an  inch  or  more  beyond  it.  Six 
sheaths  are  present  at  the  back  of  the  wrist,  and  they  surround 
the  tendons  of : — 

1.  Abductor  pollicis  longus  (Ext.  oss.  metacarp)  and  Ext.  pollicis  brevis. 

2.  Ext.  carpi  radialis  longus  and  brevis. 

3.  Ext.  pollicis  longus.     At  the  point  where  this  tendon  crosses  the  radial 
extensors  of  the  wrist,  the  two  synovial  sheaths  communicate  freely. 

4.  Ext.  digitorum  communis  and  indicis  proprius. 

5.  Ext.  digiti  quinti  proprius. 

6.  Ext.  carpi  ulnaris. 

The  characteristic  "  new  leather  creaking  "  of  teno-synovitis 
in  this  region  is  due  to  friction  between  the  inflamed  "  visceral  " 
and  parietal  layers  of  the  tendon  sheaths.  The  tendons  of  the 
radial  extensors  are  most  commonly  affected. 

Carpal  Ganglion,  which  usually  occurs  in  relation  to  the 
tendons  of  the  radial  extensors  of  the  wrist,  may  or  may  not  be 
continuous  with  their  sheaths.  According  to  some  authorities 
it  may  arise  from  a  degeneration  of  the  ligaments  in  this  region 
or  from  the  bursae  which  are  situated  immediately  beneath  the 
insertions  of  these  tendons. 

The  Dorsal  Subaponeurotic  Space. — On  the  dorsum  of  the 
hand  the  extensor  tendons  of  the  ringers  are  united  to  one 
another  by  oblique  bands  in  such  a  way  as  to  form  with  the  deep 
fascia  an  aponeurotic  sheet,  which  is  attached,  on  each  side, 
to  the  borders  of  the  second  and  fifth  metacarpals.  The  dorsal 
subaponeurotic  space  (Kanavel)  lies  between  this  sheet  and  the 
dorsal  surfaces  of  the  medial  four  metacarpals  and  interosseous 
muscles.  Septic  infection  of  the  space  is  generally  primary, 
following  wounds  on  the  dorsum.  It  may  be  involved  secondarily 
to  infections  of  the  middle  palmar  space  (p.  90),  but  it  is  never 
infected  from  the  thenar  space  (p.  90).  When  pus  collects  in 
this  situation  it  is  limited  distally  at  the  metacarpo-phalangeal 


92  THE  SUPERIOR  EXTREMITY 

joints  and  proximally,  at  the  bases  of  the  metacarpal  bones,  by 
fibrous  partitions.  On  each  side  it  is  limited  opposite  the 
borders  of  the  second  and  fifth  metacarpal  bones.  Incisions 
through  the  aponeurosis  are  made  between  the  tendons  distally 
and  run  transversely,  so  that  they  may  be  kept  open  by 
the  traction  of  the  extensor  tendons,  thus  ensuring  good 
drainage. 

In  infections  of  the  middle  palmar  space,  "  through  and 
through  "  drainage  is  obtained  through  the  fourth  interosseous 
space  and  the  dorsal  aponeurosis. 

Insertion  of  the  Digital  Extensor  Tendons. — The  tendons 
of  the  extensor  digitorum  communis  form  a  strong  expansion 
on  the  dorsum  of  the  knuckles  and  first  phalanx,  which  fuses 
with  the  dorsal  surface  of  the  capsule  of  the  metacarpo-phalangeal 
joint.  Into  this  expansion  are  inserted  the  tendons  of  the 
lumbricals  and  interossei.  On  the  index  and  the  little  fingers 
the  expansion  is  strengthened  by  the  tendons  of  the  extensor 
indicis  and  quinti  digiti  proprius,  which  blend  with  it.  The 
central  portion  of  the  expansion  is  inserted  into  the  base  of  the 
second  phalanx,  while  the  collateral  portions  pass  to  the  terminal 
phalanx. 

When  pus  collects  under  the  dorsal  expansion  it  cannot 
spread  on  to  the  dorsum  of  the  hand  until  it  has  infected  the 
metacarpo-phalangeal  joint. 

Radial  Artery. — On  leaving  the  forearm  the  radial  artery 
winds  round  the  radial  side  of  the  wrist  lying  on  the  radial 
collateral  ligament.  It  crosses  the  dorsal  surface  of  the  navicular 
and  the  os  multangulum  majus  (trapezium),  and  then  passes 
forwards  into  the  palm  at  the  proximal  end  of  the  first  inter- 
osseous  space  to  form  the  deep  volar  arch  (Fig.  30). 

The  radial  artery  appears  in  the  palm  between  the  transverse 
and  the  oblique  heads  of  the  adductor  pollicis,  and  forms  the 
deep  volar  arch  by  joining  the  deep  branch  of  the  ulnar  artery. 
The  arch  lies  deep  to  the  flexor  tendons  and  their  synovial  sheaths, 
and,  if  haemorrhage  from  it  cannot  be  controlled  by  pressure, 
etc.,  recourse  is  usually  had  to  ligature  of  the  ulnar  and  radial 
arteries.  In  this  case  the  circulation  is  gradually  re-established 
through  the  volar  and  dorsal  interosseous  arteries  (p.  71). 

The  deep  arch,  which  lies  one  finger's-breadth  proximal  to 
the  superficial  arch,  sends  branches  proximally  to  join  the  volar 
carpal  arch,  and  distally  to  join  the  digital  arteries. 

Incisions  on  the  Fingers. — Incisions  on  the  palmar  aspect 


THE  HAND  93 

of  the  fingers  are  made  in  the  middle  line  to  avoid  injuring  the 
digital  vessels  and  nerves. 

Incisions  on  the  dorsal  aspect  of  the  first  phalanx  should  be 
confined,  if  possible,  to  the  ulnar  side  to  avoid  injuring  the 
attachment  of  the  lumbrical  muscle  (p.  84).  In  the  case  of 
the  second  phalanx,  dorsal  incisions  may  be  made  to  either  side 
of  the  extensor  tendon.  Septic  infection  on  the  dorsal  surface 
of  the  terminal  phalanx  is  usually  of  the  nature  of  an  onychia 
and  involves  the  nail  bed.  It  may  spread  to  the  bone  unless 
full  exit  is  given  to  the  pus  by  removal  of  the  nail. 

Ossification  of  the  Metacarpals  and  Phalanges.  —  The 
shafts  and  distal  extremities  of  the  phalanges  ossify  from  primary 
centres ;  the  proximal  extremities  from  separate  epiphyses, 
which  ossify  during  the  third  year  and  unite  with  the  shafts  at 
twenty.  The  metacarpal  bone  of  the  thumb  ossifies  in  the  same 
way  as  a  phalanx,  but  in  the  other  metacarpal  bones  the  bases 
and  shafts  are  derived  from  the  same  primary  centres,  while 
the  heads  are  formed  by  separate  epiphyses,  ossifying  at  three 
and  uniting  with  the  diaphyses  at  twenty. 

Tuberculous  Dactylitis  usually  attacks  the  centres  of  the 
shafts  of  the  metacarpals  and  phalanges  instead  of  their  ex- 
tremities, probably  because  the  nutrient  artery  on  entering  the 
bone  at  once  breaks  up  into  small  branches,  whereas  in  the  other 
long  bones  it  divides  into  large  ascending  and  descending 
branches.  Owing  to  their  mode  of  ossification,  the  diaphyses 
of  these  bones  cannot  be  completely  resected  subperiosteally 
without  opening  one  of  the  joints.  On  this  account,  after  the 
periosteum  has  been  elevated,  the  bone  is  divided  close  to 
the  extremity  which  has  no  epiphysis.  The  diaphysis  can 
then  be  lifted  and  broken  away  from  the  epiphyseal  cartilage 
at  the  opposite  extremity. 

The  Metacarpo-Phalangeal  Joints  possess  volar  and  collateral 
ligaments,  but  the  dorsal  ligament  is  replaced  by  the  extensor 
expansion.  The  volar  accessory  (glenoid)  ligament  is  a  plate 
of  fibrocartilage,  which  is  firmly  attached  to  the  proximal 
phalanx  but  only  feebly  connected  with  the  metacarpal  bone. 

Dorsal  Dislocation  of  the  Thumb,  at  its  metacarpo- 
phalangeal  joint  (Hey's  dislocation),  is  produced  by  extreme 
dorsi-flexion  of  the  thumb.  The  volar  accessory  ligament  gives 
way  at  its  weak  proximal  attachment,  and  the  phalanx  passes 
backwards,  carrying  the  ligament  with  it.  The  distal  phalanx 
is  flexed  by  the  flexor  pollicis  longus.  Hyper-extension  at  the 


94  THE  SUPERIOR  EXTREMITY 

metacarpo-phalangeal  joint  is  primarily  due  to  the  causative 


FJG.  33. — The  Hand  of  a  Child  of  three,  showing  Tuberculous  Dactylitis. 
The  first  metacarpal  and  the  proximal  phalanx  of  the  index  finger  are 
affected  by  the  disease.  Note  the  stage  of  ossification  of  the  carpus  and 
metacarpus. 

force,  and  is  maintained  by  the  abductor  pollicis  brevis,  whose 


THE  HAND  95 

"  line  of  pull  "  falls  behind  the  point  of  contact  of  the  phalanx 
with  the  head  of  the  metacarpal.  As  soon  as  manipulations 
have  succeeded  in  bringing  the  line  of  pull  in  front  of  the  point 
of  contact,  hyper-extension  is  replaced  by  a  slight  degree  of 
flexion. 

Difficulty  in  reduction  may  be  caused  (i)  by  the  head  of  the 
metacarpal  being  caught  between  the  flexor  pollicis  brevis  and 
the  adductor  pollicis,  (2)  by  the  tendon  of  the  flexor  pollicis 
longus  slipping  over  to  the  ulnar  side  of  the  metacarpal,  or  (3) 
by  the  interposition  of  the  volar  accessory  ligament  between  the 
two  bones.  Reduction  is  brought  about  by  traction  and  hyper- 
extension  in  order  to  allow  the  torn  end  of  the  volar  ligament 
to  pass  over  the  head  of  the  metacarpal  before  the  thumb  is 
flexed  to  the  palm. 

Development  of  Fingers. — During  the  sixth  week  of  foetal  life,  four  linear 
furrows  appear  on  the  distal  part  of  the  upper  limb.  These  deepen  and 
finally  become  clefts,  which  separate  the  digits  from  one  another.  The 
furrows  may  be  incomplete,  giving  rise  to  webbing  of  the  ringers  (syn- 
dactylisni) ;  or  extra  furrows  may  develop  and  produce  supernumerary  digits 
(polydactylism).  In  the  former  case  the  furrow  may  be  so  shallow  that  the 
bones  of  contiguous  digits  are  fused  together. 


THE   BRACHIAL   PLEXUS  AND   ITS 
BRANCHES. 

The  brachial  plexus  is  formed  by  the  anterior  rami  (anterior 
primary  divisions)  of  the  lower  four  cervical  and  the  first  thoracic 
nerves,  assisted  by  small  twigs  from  the  fourth  cervical  and 
the  second  thoracic  nerves.  The  twig  from  the  fourth  cervical 
joins  the  fifth,  which  then  unites  with  the  sixth,  constituting  the 
Upper  Trunk  of  the  Plexus.  The  seventh  cervical  alone  forms 
the  Middle  Trunk.  The  eighth  cervical  and  the  first  thoracic 
unite  to  form  the  Lower  Trunk.  Each  of  these  trunks  divides 
into  an  anterior  and  a  posterior  branch,  and  the  three  posterior 
branches  join  to  form  the  Posterior  Cord  of  the  Plexus.  The 
anterior  branches  of  the  upper  and  middle  trunks  join  to  form 
the  Lateral  Cord,  while  the  anterior  branch  of  the  lower  trunk 
forms  the  Medial  Cord  (Fig.  34). 


96 


THE  SUPERIOR  EXTREMITY 


Supra- clavicular  Branches. 

Long  Thoracic  Nerve  (of  Bell),  C.  5,  6,  and  7. 
Dorsalis  Scapulae  (Nerve  to  Rhomboids),  C.  5. 
Nerve  to  Subclavius,  C.  5  and  6. 
Supra-scapular,  C.  5  and  6. 

Infra- clavicular  Branches. 

(  Lateral  Anterior  Thoracic  (C.  5,  6,  and  7). 
Lateral  Cord  -!  Lateral  Head  of  Median  (C.  5,  6,  and  7). 
{  Musculo-Cutaneous  (C.  5,  6,  and  7). 


Scalenus  anterior  and  longus  colli 
Scalenus  medius  and  posterior 

Phrenic  nerve 

Seal,  anterior  and  longus  colli 

Seal,  medius  and  posterior 


Seal,  anterior  and  longus  colli 
Seal,  medius  and  posterior 


Scalenus  anterior  and  longus  colli 
Scalenus  medius  and  posterior 


FIG.  34. — Diagram  of  Brachial  Plexus.      (After  Paterson.) 

{Medial  Anterior  Thoracic  (C.  8  and  T.  i). 
Medial  Cutaneous  of  Arm  (Lesser  Internal  Cutaneous)  (T.  i). 
Medial  Cutaneous  of  Forearm  (Internal  Cutaneous)  (C.  8 
and  T.  i). 
Medial  Head  of  Median  (C.  8  and  T.  i). 
Ulnar  (C.  8  and  T.  T). 


Posterioi 


THE  BRACHIAL  PLEXUS  97 


f 


(Upper  (Short)  Subscapular  (C.  5  and  6). 
Lower  (Middle)  Subscapular  (C.  5  and  6). 
Thoraco-dorsal  (Long  Subscapular)  (C.  6,  7,  and  8). 
Radial  (Musculo-Spiral)  (C.  5,  6,  7,  and  8). 
Axillary  (Circumflex)  (C.  5  and  6). 


Lesions  of  the  plexus  or  of  its  constituent  parts  are  followed 
by  alterations  in  the  motor  and  sensory  functions  in  the  area 
supplied.  It  must  be  remembered  that  the  areas  supplied  by 
cutaneous  nerves  overlap  one  another  to  a  considerable  extent, 
and  that  section  of  a  single  cutaneous  nerve  will  produce  an  area 
of  altered  sensibility  which  is  much  smaller  than  the  area  of 
anatomical  supply  of  the  nerve  involved. 

Note. — Three  varieties  of  sensibility  are  described  by  Head  and  Sherren. 
(i)  Deep  Sensibility.  This  form  of  sensation  is  conveyed  by  fibres  which 
run  with  the  motor  nerves  and  associate  themselves  with  muscles,  tendons, 
periosteum,  and  ligaments.  By  these  fibres  coarse  tactile  stimuli  are  recog- 
nised even  after  division  of  cutaneous  nerves.  Deep  sensibility  disappears 
when  a  nerve  is  cut  proximal  to  the  origin  of  its  motor  branches,  or  when  the 
tendons,  which  convey  the  nerve  fibres,  are  severed.  (2)  Protopathic 
Sensibility.  Painful  cutaneous  stimuli  and  extremes  of  temperature  are 
recognised  by  this  form  of  sensibility,  which  is  conveyed  by  the  cutaneous 
nerves.  The  areas  of  protopathic  supply  by  different  nerves  overlap  one 
another  to  a  considerable  extent.  (3)  Epicritic  Sensibility.  This  form 
of  sensation,  which  is  also  conveyed  by  the  cutaneous  nerves,  responds  to 
light  touch,  localises  accurately  all  painful  and  tactile  stimuli,  and  recognises 
intermediate  degrees  of  temperature. 

For  a  full  and  complete  discussion  of  the  various  forms  of  sensation 
the  reader  is  referred  to  the  works  of  the  authors  referred  to  above. 

Lesions  of  the  Supra-clavicular  Branches.— The  Long 
Thoracic  Nerve  (of  Bell)  (C.  5,  6,  and  7)  and  the  Dorsalis 
Scapulae  Nerve  (to  the  Rhomboids)  (C.  5)  both  arise  so  close 
to  the  inter  vertebral  foramina  that  they  are  rarely  injured  in 
tears  of  the  plexus.  The  latter  nerve  may  be  injured  in  removal 
of  lymph  glands  from  behind  the  posterior  belly  of  the  omo- 
hyoid,,  unless  the  pervertebral  fascia  on  the  floor  of  the  posterior 
triangle  of  the  neck  is  left  intact  (p.  135).  In  paralysis  of  the 
rhomboid  muscles  the  scapula  on  the  injured  side  lies  slightly 
lower  than  it  should;  and  the  inferior  angle  is  at  a  greater  distance 
from  the  median  plane  than  it  is  on  the  sound  side. 

The  Long  Thoracic  Nerve  (of  Bell)  (p.  131)  may  be  injured 
in  operations  involving  the  axilla  (p.  35)  or  by  the  pressure  of 
weights  carried  on  the  shoulder.  In  the  latter  case  the  dorsalis 
scapulae  nerve  (to  the  rhomboids)  and  the  branches  of  C.  3  and 
C.  4 — both  motor  and  sensory — which  cross  the  posterior  triangle 
of  the  neck  (p.  126),  may  also  be  injured.  Owing  to  this  com- 

7 


98  THE  SUPERIOR  EXTREMITY 

plication,  paralysis  of  the  serratus  anterior  (s.  magnus)  is 
frequently  accompanied  by  paralysis  of  the  lower  part  of  the 
trapezius  and  by  pain,  which  radiates  over  the  distribution  of 
C.  3  and  C.  4.  When  the  serratus  anterior  is  paralysed  alone, 
the  patient  is  unable  to  flex  the  humerus  above  the  level  of 
the  shoulder.  If  his  arm  is  passively  flexed  above  that  level, 
forward  pushing  movements  cannot  be  performed,  and  attempts 
to  produce  them  cause  marked  winging  of  the  scapula.  All  the 
other  movements,  including  forward  pushing  below  the  shoulder, 
are  intact,  and,  although  the  latter  is  weaker,  it  does  not  produce 
winging  of  the  scapula  (Sherren).  When  in  addition  the  lower 
fibres  of  the  trapezius  (C.  3  and  4)  are  affected,  no  forward 
pushing  movement  can  be  performed,  and  marked  winging  of 
the  scapula  results  on  its  being  attempted. 

The  Supra-scapular  Nerve  (p.  127)  arises  from  the  upper 
trunk  of  the  plexus  (C.  5  and  6)  and  supplies  the  supra-  and 
the  infra-spinatus.  When  it  is  injured  alone — a  rare  occurrence — 
the  resulting  disability  is  slight,  as  lateral  rotation  of  the  humerus, 
though  definitely  weakened,  can  still  be  performed  by  the 
teres  minor  and  the  posterior  fibres  of  the  deltoid.  In  Erb- 
Duchenne  paralysis  (p.  99)  the  lesion  usually  occurs  proximal 
to  the  origin  of  the  supra-scapular  nerve,  which  is  therefore 
involved. 

Lesions  of  the  Brachial  Plexus. —  As  the  brachial 
plexus  passes  towards  the  axilla  its  constituent  parts  converge 
on  one  another  at  the  outer  border  of  the  first  rib,  the  upper 
having  a  downward  and  the  lower  an  upward  inclination.  On 
this  account  violence  applied  to  the  shoulder  in  a  downward 
direction  will  cause  a  stretching  or  tearing  of  the  upper  trunk 
(Erb-Duchenne  type,  p.  99),  and  violence  applied  in  the  opposite 
direction  will  affect  the  lower  trunk  in  a  similar  manner  (Klumpke 
type,  p.  100). 

Supra-clavicular  lesions  of  the  plexus  are  generally  brought 
about  as  the  result  of  trauma  (e.g.  in  complicated  labour,  in 
artificial  respiration,  when  a  person  falling  from  a  height  grasps 
something  to  save  himself,  or  when  the  arm  of  an  unconscious 
patient  hangs  unsupported  over  the  edge  of  an  operating  table), 
but  they  may  also  occur  from  the  pressure  of  a  cervical  rib. 

Haemorrhagic  extravasation  or  effusion  into  a  nerve  trunk  is 
quite  sufficient  to  produce  a  temporary  paralysis  of  the  muscles 
supplied.  Rapid  and  complete  recovery  differentiates  this 
condition  from  an  actual  rupture  of  nerve  fibres. 


THE  BRACHIAL  PLEXUS  99 

The  whole  plexus  may  be  injured,  but  unless  the  nerves 
are  torn  close  to  the  intervertebral  foramina,  the  rhomboids 
and  the  serratus  anterior  escape.  Sometimes  all  the  trunks 
of  the  plexus  are  torn,  and  when  this  occurs  distal  to  the  origin 
of  the  supra-scapular  nerve,  the  supra-  and  the  infra-spinatus 
escape  paralysis.  The  examination  of  these  muscles  and  of  the 
condition  of  the  pupil  (pp.  98,  125)  helps  to  determine  the  site 
of  all  such  extensive  lesions. 

In  these  injuries,  epicritic  and  protopathic  sensibility  are  lost 
over  the  whole  arm,  except  in  the  areas  supplied  by  the  descend- 
ing branches  of  the  cervical  plexus  (C.  3  and  4)  on  the  lateral  side 
of  the  arm,  and  by  the  intercosto-brachial  nerve  on  the  medial 
side  of  the  arm  (Fig.  13).  The  full  area  of  supply  of  these 
nerves  is  demonstrated  as  the  overlapping  nerves  are  all 
paralysed. 

It  is  important  to  remember  that  limited  haemorrhage  into 
the  spinal  medulla,  from  disease  or  accident,  or  the  onset  of 
acute  anterior  poliomyelitis  may  give  rise  to  clinical  signs  similar 
to  those  produced  by  injuries  of  the  plexus.  It  is  necessary, 
therefore,  to  examine  the  lower  limbs  for  signs  of  motor  and 
sensory  disturbance  in  order  to  determine  whether  the  plexus 
or  the  spinal  medulla  is  the  site  of  the  lesion. 

Erb-Duchenne  or  Upper  Arm  Type  of  Paralysis. — This 
condition  results  usually  from  downward  traction  of  the  shoulder 
during  complicated  labour.  The  upper  trunk  is  torn  proximal 
to  the  origin  of  the  supra-scapular  nerve,  but  distal  to  the  origins 
of  the  long  thoracic  nerve  (of  Bell)  and  the  dorsalis  scapulce  nerve 
(to  the  rhomboids).  The  serratus  anterior  and  the  rhomboids 
consequently  escape,  but  all  the  other  muscles  innervated  by 
C.  5  and  C.  6  are  paralysed  (p.  106).  The  deltoid,  teres  minor, 
and  infra-spinatus  are  all  affected,  and  the  arm  is  rotated  medially 
by  the  latissimus  dorsi  (C.  6,  7,  and  8)  and  the  sternal  head  of  the 
pectoralis  major,  the  latter  owing  to  its  supply  from  the  medial 
anterior  thoracic  nerve  (C.  8  and  T.  i).  The  biceps  and  the 
brachio-radialis  are  paralysed  and  the  brachialis  (C.  5,  6,  and  7) 
is  greatly  weakened.  The  elbow  is  generally  extended  owing 
to  the  action  of  the  triceps  (C.  7  and  8),  which  usually  escapes. 
The  supinators  are  all  paralysed  and  the  forearm  is  pronated 
by  the  pronator  quadratus  (C.  7,  8,  and  T.  i)  alone,  the  pronator 
teres  being  supplied  by  C.  6.  The  radial  extensors  of  the  wrist 
being  affected,  the  hand  is  deviated  to  the  ulnar  side,  but  all  the 
other  movements  of  the  wrist  and  fingers  are  unchanged. 

7a 


ioo  THE  SUPERIOR  EXTREMITY 

As  the  arm  is  fully  pronated,  the  extensor  digitorum  com- 
munis  and  carpi  ulnaris  (C.  6,  7,  and  8)  may  subsequently  be 
able  to  produce  a  small  degree  of  flexion  at  the  elbow. 

When  the  lesion  is  confined  to  the  anterior  ramus  (primary 
division)  of  C.  5,  no  sensory  changes  can  be  discovered;  as  it  is 
not  responsible  for  the  exclusive  supply  of  any  definite  area  of 
skin.  If  C.  6  also  is  involved,  there  is  usually  some  loss  of 
epicritic  sensibility  on  the  lateral  aspects  of  the  arm  and  forearm. 

In  the  treatment  of  this  and  other  similar  conditions,  it  must 
be  remembered  that  unless  the  paralysed  muscles  are  relaxed 
they  will  become  overstretched  by  the  unopposed  action  of  the 
unparalysed  antagonistic  muscles. 

Surgical  approach  to  the  plexus  is  described  on  p.  127. 

Klumpke's  Paralysis  :  Lower  Arm  Type. — This  condition 
results  from  upward  traction  on  the  shoulder,  e.g.  when  a  man 
falling  from  a  height  seizes  something  to  save  himself,  or  in  a 
breech  presentation  when  the  arms  are  carried  up  above  the 
head.  The  lesion  usually  affects  the  first  thoracic  nerve,  but  it 
may  involve  the  whole  of  the  lower  trunk  (C.  8  and  T.  i).  The 
intrinsic  muscles  of  the  hand  are  paralysed  and  a  characteristic 
claw-hand  develops.  (The  fingers  are  hyper-extended  at  the 
metacarpo-phalangeal  joints  and  flexed  at  the  inter-phalangeal 
joints.)  If  the  whole  of  the  lower  trunk  is  affected  the  flexors 
and  extensors  of  the  fingers  are  paralysed  in  addition  (Sherren). 

Diminution  of  sensibility  occurs  over  the  medial  side  of  the 
arm,  forearm,  and  hand,  the  area  of  protopathic  loss  being 
greater  than  the  area  of  epicritic  loss.  When  the  first  thoracic 
nerve  is  injured  proximal  to  the  point  at  which  it  sends  off  the 
white  ramus  communicans  to  the  first  thoracic  ganglion  of  the 
sympathetic,  the  cilio-spinal  reflex  (p.  125)  is  abolished. 

A  Cervical  Rib  (p.  128)  may  produce  a  supra-clavicular 
lesion  of  the  brachial  plexus.  In  these  cases  the  symptoms 
appear  usually  on  the  right  side  and  indicate  involvement  of 
the  lower  trunk.  No  pupillary  changes  are  present,  as  T.  i 
is  affected  beyond  the  origin  of  its  white  ramus  communicans. 
Neuralgic  pain  radiates  down  the  ulnar  side  of  the  upper  limb 
in  the  areas  supplied  by  the  nerves  involved  (Fig.  14),  and 
there  may  be  some  epicritic  loss  in  the  same  situation.  Wasting 
and  progressive  paresis  occur  in  the  intrinsic  muscles  of  the 
hand.  Recent  observations  have  shown  that  the  same  symptoms 
may  be  produced  by  the  pressure  of  the  first  rib. 

Injuries  to  the  Cords  of  the  Plexus.— The  Medial 


THE  BRACHIAL  PLEXUS  101 

Cord  may  be  torn  or  stretched  in  subcoracoid  dislocation  of 
the  humerus  or  by  the  "  heel  in  axilla  "  method  of  reduction. 
Sensory  changes  are  found  in  the  areas  supplied  by  the  ulnar, 
and  the  medial  cutaneous  nerves  of  the  arm  and  forearm  (Fig. 
12).  All  the  muscles  supplied  by  the  medial  cord  are  paralysed, 
i.e.  the  intrinsic  muscles  of  the  hand,  supplied  by  the  ulnar  and 
medial  head  of  the  median,  and  the  flexor  carpi  ulnaris  and  the 
ulnar  part  of  the  flexor  digitorum  profundus,  both  supplied  by 
the  ulnar  nerve. 

The  Lateral  Cord  may  be  injured  in  the  same  way.  All 
the  muscles  supplied  by  the  musculo-cutaneous  nerve  (biceps, 
coraco-brachialis,  and  brachialis,  partly)  and  by  the  lateral  head 
of  the  median  (superficial  and  deep  muscles  of  front  of  forearm) 
(p.  72)  are  paralysed.  Partial  epicritic  insensibility  exists  in 
the  areas  supplied  by  the  musculo-cutaneous  and  median  nerves 
(Fig.  12). 

Injury  of  the  Posterior  Cord  produces  all  the  signs  of 
combined  radial  (musculo-spiral)  and  axillary  (circumflex) 
paralyses. 

Lesions  of  the  Infra-clavicular  Branches  of  the 
Plexus.  Axillary  (Circumflex)  Nerve. — When  this  nerve  is 
paralysed  (p.  39)  the  deltoid  atrophies  and  the  bony  land- 
marks become  prominent — a  condition  which  must  be  differ- 
entiated from  wasting  of  the  muscle  following  disease  of  the 
shoulder-joint.  Lateral  rotation  is  not  greatly  affected  by  the 
paralysis  of  the  teres  minor,  but  abduction  can  only  be  produced 
by  the  supra-spinatus.  A  marked  loss  of  epicritic  and  proto- 
pathic  sensibilities  over  the  distal  part  of  the  deltoid  always 
accompanies  injury  to  the  axillary  (circumflex)  nerve. 

The  Radial  (Musculo-Spiral)  Nerve  may  be  pressed  on  in 
the  axilla,  e.g.  "  crutch "  and  "  Saturday-night  "  paralysis. 
It  is  damaged  in  8  per  cent  of  fractures  of  the  distal  two- 
thirds  of  the  shaft  of  the  humerus,  either  at  the  time  of  the 
accident  or  in  the  subsequent  formation  of  callus,  and  it  has 
occasionally  been  injured  in  wiring  ununited  fractures  of  the 
humerus. 

The  Dorsal  Interosseous  Nerve  is  sometimes  injured  in 
fractures  of  the  neck  of  the  radius  and  in  dislocations  of  that 
bone.  It  may  be  cut  in  operations  which  involve  incisions 
into  the  supinator  (s.  brevis)  (p.  65).  The  Superficial  Branch 
of  the  Radial  Nerve  (Radial  Branch  of  Musculo-Spiral)  may  be 
injured  in  wounds  about  the  lateral  and  dorsal  aspects  of  the 

7b 


102  THE  SUPERIOR  EXTREMITY 

wrist,  but  if  no  other  nerves  are  involved,  no  sensory  change  is 
apparent  (vide  infra). 

Injury  to  the  Radial  (Musculo-Spiral)  nerve  occurs  most 
commonly  in  its  distal  third  beyond  the  origin  of  its  cutaneous 
branches  and  of  the  nerve-supply  of  the  triceps  and  the  anconseus. 
All  the  remaining  muscles  supplied  directly  by  the  radial 
(musculo-spiral)  nerve  (p.  73)  and  indirectly  by  its  deep  branch 
(posterior  interosseous  nerve)  are  paralysed,  and  the  characteristic 
deformity  of  "  Drop  Wrist  "  develops.  The  patient  is  unable 
to  extend  his  wrist  or  fingers,  but,  if  the  first  phalanges  are 
supported  when  he  attempts  to  do  so,  the  lumbricals  and  interossei, 
which  act  in  harmony  with  the  extensor  apparatus,  will  extend 
the  fingers  at  the  inter -phalangeal  joints  (p.  84). 

No  sensory  changes  accompany  injury  to  the  radial  (musculo- 
spiral)  nerve  in  its  distal  third.  Its  superficial  branch  (radial 
nerve)  is  paralysed,  but  on  account  of  the  communications 
which  it  establishes  with  other  nerves,  no  change  of  sensibility 
can  be  determined. 

Note. — The  dorsal  branch  of  the  lateral  cutaneous  (from  the  musculo- 
cutaneous  nerve),  the  superficial  (radial)  branch  of  the  radial  (musculo- 
spiral)  nerve,  and  the  dorsal  cutaneous  nerve  of  the  forearm  (lower  external 
cutaneous  branch  of  the  musculo-spiral)  communicate  with  one  another 
and  overlap  to  such  an  extent  that  no  sensory  symptoms  are  produced  by 
section  oj  any  one  of  the  nerves  by  itself.  If  any  two  are  injured  there  is  some 
loss  of  epicritic  and  protopathic  sensibility,  extending  from  the  bases  of  the 
lateral  three  digits  to  the  dorsum  of  the  wrist,  but  complete  epicritic  and 
protopathic  loss  in  this  area  occurs  only  after  division  of  all  three  (Sherren). 

When  the  dorsal  interosseous  nerve  is  injured,  the  motor 
symptoms  are  the  same  as  those  described  above,  except  that 
the  brachio-radialis  and  extensor  carpi  radialis  longus  escape. 
As  a  result,  the  patient  is  able  to  extend  the  wrist,  but  the 
movement  is  weak. 

The  "  Drop  Wrist  "  of  lead  poisoning  can  be  differentiated 
from  both  the  above  varieties,  as  the  brachio-radialis  is  not 
affected  while  the  extensor  carpi  radialis  longus  is  paralysed. 

Musculo-Cutaneous  Nerve. — The  main  trunk  of  this  nerve 
is  rarely  injured  by  itself,  but  the  cutaneous  portion  or  one  of 
its  branches  may  be  cut  in  incisions  and  wounds  of  the  forearm. 

In  injury  of  the  main  trunk,  the  biceps  and  the  coraco- 
brachialis  are  paralysed  and  the  brachialis  is  weakened  (p.  41). 
Flexion  of  the  forearm  is  still  possible,  and  is  performed  by  the 
krachialis  and  the  superficial  flexors  of  the  forearm  when  the 
hand  is  supine,  but,  when  the  forearm  is  in  the  prone  or  mid- 


THE  BRACHIAL  PLEXUS  103 

prone  position,  the  brachio-radialis  and  the  extensor  carpi 
radialis  longus  assist  in  its  production. 

Epicritic  and  protopathic  insensibility  occurs  over  the 
radial  half  of  the  forearm.  In  front,  the  boundary  line  is  very 
constant  and  runs  from  the  line  of  the  ring  finger  at  the  wrist 
to  the  tendon  of  the  biceps.  Dorsally  the  boundary  line  is  not 
so  definite  and  the  insensitive  area  varies  inversely  with  the 
size  of  the  dorsal  cutaneous  nerve  of  the  forearm  (lower  external 
cutaneous  branch  of  the  musculo-spiral  nerve). 

Section  of  the  cutaneous  portion  of  the  musculo-cutaneous 
nerve  produces  the  same  sensory  symptoms  as  those  which 
result  from  injury  of  the  main  trunk.  Section  of  its  volar  or 
of  its  dorsal  branch  produces  no  change  in  sensibility  owing  to 
the  overlapping  by  adjoining  nerves. 

Medial  Cutaneous  Nerve  of  the  Forearm  (Internal 
Cutaneous  Nerve). — When  the  main  trunk  of  this  nerve  is  cut, 
epicritic  and  protopathic  sensibility  are  lost  over  the  ulnar  side 
of  the  forearm,  but  if  one  of  the  terminal  branches  is  injured, 
epicritic  sensibility  alone  is  lost  over  the  area  involved. 

Ulnar  Nerve. — The  ulnar  nerve  is  liable  to  injury  at  the 
wrist,  where  it  is  exposed  to  cuts  and  stabs,  and  at  the  elbow, 
where  it  may  be  involved  in  fractures,  dislocations,  or  operations 
on  the  joint. 

i.  At  the  Wrist. — The  injury  may  occur  either  proximal  or 
distal  to  the  origin  of  the  dorsal  cutaneous  branch,  and,  though 
the  motor  symptoms  are  exactly  similar,  the  sensory  changes 
are  slightly  different  in  the  two  cases. 

All  the  intrinsic  muscles  of  the  hand,  save  those  supplied 
by  the  median  nerve  (p.  86),  are  paralysed,  and  a  characteristic 
deformity  (partial  main  en  griff e)  is  produced.  In  cases  seen 
immediately  after  the  accident,  the  injury  to  the  nerve  may  be 
overlooked  when  no  tendons  are  cut,  as  the  patient  appears,  on 
superficial  examination,  to  be  able  to  perform  most  of  the 
movements  of  the  fingers.  It  is  always  essential  in  these  cases 
to  ask  the  patient  to  separate  the  fingers,  and,  if  he  is  unable  to 
do  so,  paralysis  of  the  dorsal  interossei  and  of  the  abductor 
digiti  quinti  is  at  once  discovered  and  a  more  thorough  examina- 
tion should  then  be  made. 

In  old-standing  cases,  the  paralysed  muscles  atrophy  and 
the  fingers  are  extended  at  the  metacarpo-phalangeal  joints,  as 
the  balance  between  the  flexors  and  extensors  is  lost,  owing 
to  paralysis  of  the  interossei.  In  the  little  and  ring  fingers  the 


io4  THE  SUPERIOR  EXTREMITY 

balance  is  further  upset  by  paralysis  of  the  lumbrical  muscles 
(p.  84),  and  as  the  action  of  these  muscles  on  the  dorsal  extensor 
expansion  (p.  92)  is  lost,  hyper- extension  at  the  metacarpo- 
phalangeal  joints  and  flexion  at  the  inter-phalangeal  joints 
result.  The  thumb  is  abducted  owing  to  paralysis  of  the 
adductor,  and  consequently  the  grasping  power  of  the  hand  is 
greatly  diminished. 

When  the  ulnar  nerve  is  cut  distal  to  the  origin  of  its  dorsal 
cutaneous  branch,  epicritic  sensibility  is  lost  over  the  ulnar  side 
of  the  palm,  the  palmar  aspects  of  the  little  ringer  and  ulnar  side 
of  the  ring  ringer,  and  the  dorsal  aspects  of  the  second  and  third 
phalanges  of  the  same  fingers.  Protopathic  loss  varies,  and 
deep  sensibility  is  always  present  in  these  cases  unless  many 
tendons  are  cut.  When  the  injury  occurs  proximal  to  the  origin 
of  the  dorsal  cutaneous  branch,  all  the  previous  sensory  symptoms 
are  present,  and,  in  addition,  epicritic  sensibility  is  lost  over  the 
ulnar  side  of  the  dorsum  of  the  hand  and  over  the  dorsal  aspects 
of  the  proximal  phalanges  of  the  little  finger  and  ulnar  side  of 
the  ring  finger. 

2.  At  the  Elbow. — In  injury  of  the  ulnar  nerve  at  this  site, 
the  additional  muscular  paralysis  produces  a  slight  change  in 
the  deformity  of  the  hand.  The  portion  of  the  flexor  digitorum 
profundus  destined  for  the  ring  and  little  fingers  is  paralysed, 
and  therefore  the  terminal  phalanges  of  these  fingers  are  not 
flexed,  as  in  (i),  but  are  hyper-extended  by  the  unopposed 
action  of  the  extensor  expansion.  Radial  deviation  of  the 
hand  occurs  on  flexion  of  the  wrist  owing  to  paralysis  of  the 
flexor  carpi  ulnaris. 

The  sensory  changes  are  exactly  similar  to  those  which  occur 
in  section  of  the  nerve  at  the  wrist  above  the  origin  of  the  dorsal 
cutaneous  branch.  In  addition,  there  is  some  loss  of  deep 
sensibility  on  the  ulnar  side  of  the  palm. 

Median  Nerve. — The  median  nerve  is  most  commonly  injured 
as  it  lies  between  the  tendons  of  the  palmaris  longus  and  the 
flexor  carpi  radialis  at  the  proximal  border  of  the  transverse 
carpal  ligament  (p.  67).  It  is  here  cut  by  stab-wounds,  the 
neighbouring  tendons  usually  escaping  injury. 

Motor  Symptoms. — The  abductor  and  the  flexor  pollicis 
brevis,  the  opponens  pollicis,  and  the  first  and  second  lumbricals 
are  the  only  muscles  affected.  The  thumb  cannot  be  abducted 
(p.  84),  but  the  movement  of  opposition  may  be  imitated  by 
the  flexor  pollicis  longus.  When  the  patient  is  told  to  close  the 


THE  BRACHIAL  PLEXUS  105 

hand  slowly,  the  index  and  middle  fingers  lag  behind  the  other 
two,  as  the  balance  between  the  extensors  and  flexors  is  disturbed 
by  the  lumbrical  paralysis  (see  Ulnar  Nerve,  p.  103).  Hyper- 
extension  of  the  index  and  middle  fingers  at  the  metacarpo- 
phalangeal  joints  and  adduction  of  the  thumb  are  the 
characteristic  features  of  the  condition  when  the  hand  is  at  rest. 

Sensory  Symptoms. — Epicritic  sensibility  is  lost  over  the 
palm  of  the  hand  and  over  the  area  supplied  by  the  digital 
branches.  On  the  dorsal  aspect,  epicritic  sensibility  is  lost  over 
the  second  and  third  phalanges  of  the  same  fingers,  but  there  is 
no  sensory  change  on  the  dorsum  of  the  thumb.  The  radial 
side  of  the  thenar  eminence  is  not  affected.  If  many  tendons 
are  cut,  as  well  as  the  nerve,  deep  sensibility  is  interfered  with, 
and  there  is  additional  muscular  paralysis. 

When  the  median  nerve  is  injured  proximal  to  the  bend  of 
the  elbow,  the  sensory  symptoms  are  the  same  as  those  described 
above,  but,  in  addition,  deep  sensibility  is  diminished  over  the 
palmar  aspect  of  the  hand  and  fingers.  The  amount  of  muscular 
paralysis  is  greatly  increased,  as  the  nerve  is  injured  proximal 
to  the  origin  of  the  branches  supplying  the  muscles  on  the  front 
of  the  forearm  (p.  72).  True  pronation  is  lost,  but  the  brachio- 
radialis  carries  the  forearm  from  the  supine  into  the  mid-prone 
position  and  then,  if  the  arm  is  abducted,  the  weight  of  the 
hand  can  complete  the  action.  Flexion  of  the  wrist  with  ulnar 
deviation  is  performed  by  the  flexor  carpi  ulnaris  and  the  ulnar 
half  of  the  flexor  digitorum  profundus.  The  thumb  is  still 
adducted,  but  the  terminal  phalanx  is  kept  extended  owing  to 
paralysis  of  the  flexor  pollicis  longus.  The  index  and  middle 
fingers  are  practically  useless,  as  no  flexion  is  possible  at  the 
inter-phalangeal  joints,  and  the  interossei — which  are  the  only 
flexor  muscles  unaffected — are  but  feeble  flexors  of  the  metacarpo- 
phalangeal  joints  when  they  have  to  initiate  the  movement. 
On  the  other  hand,  the  ring  and' little  fingers  are  weakened  only 
by  the  loss  of  the  flexor  digitorum  sublimis  tendons. 

Segmental  Inner  vation  of  the  Muscles  of  the  Superior 
Extremity. — The  statements  made  in  the  foregoing  pages 
regarding  the  segmental  innervation  of  the  individual  muscles 
are  substantially  in  agreement  with  the  descriptions  given  in 
modern  anatomical  text-books,  but  they  differ,  in  many  instances, 
from  the  descriptions  given  by  Kocher,  whose  views  are  based 
on  clinical  data.  His  conclusions  are  embodied  in  the  following 
table : 


io6 


THE  SUPERIOR  EXTREMITY 


Nerve. 


Muscles. 


C.  V. 


C.  VI. 


C.  VII. 
C.  VIII. 
T.  I. 


Rhomboids,  supra-  and  infra-spinatus,  deltoid,  teres 
minor,  coraco-brachialis,  biceps,  brachialis,  brachio- 
radialis,  and  supinator.  (Abductors  and  lateral 
rotators  of  the  shoulder ;  flexors  and  supinators  of 
forearm.) 

Pectoralis  major  and  minor,  subscapularis,  latissimus 
dorsi,  teres  major,  serratus  anterior,  triceps,  pronator 
teres,  and  pronator  quadratus.  (Adductors  and 
medial  rotators  of  shoulder  ;  extensors  and  pronators 
of  forearm.) 

Extensors  and  flexors  of  the  wrist. 
Long  flexors  and  extensors  of  the  fingers. 
Small  muscles  of  the  hand. 


THE  NECK  107 


THE    HEAD   AND    NECK. 


THE  NECK. 

Surface  Landmarks. — The  sterno-mastoid  muscle,  which  is 
the  most  important  landmark  in  the  neck,  forms  an  elevation, 
i£  inches  wide,  between  the  anterior  and  posterior  triangles. 
If  its  anterior  border  is  traced  upwards,  the  mastoid  process 
can  be  felt  lying  under  cover  of  the  lobule  of  the  ear,  rather  more 
than  one  inch  above  and  behind  the  angle  of  the  mandible. 
On  deep  pressure,  midway  between  these  two  bony  points, 
pain  is  elicited  owing  to  the  compression  of  the  skin  and  parotid 
gland  against  the  subjacent  transverse  process  of  the  atlas  vertebra. 

In  the  anterior  median  line  of  the  neck  the  laryngeal  promin- 
ence, due  to  the  forward  projection  of  the  thyreoid  cartilage, 
forms  a  conspicuous  landmark,  which  is  more  prominent  in 
men  than  in  women.  The  greater  cornu  of  the  hyoid  bone  is  situ- 
ated midway  between  the  mastoid  process  and  the  laryngeal 
prominence,  but,  owing  to  its  mobility,  it  cannot  be  made  out 
unless  the  bone  is  steadied  by  placing  a  finger  at  the  same  level 
on  the  opposite  side  of  the  neck.  When  the  greater  cornu  is 
traced  forwards,  the  body  of  the  hyoid  bone  can  be  examined. 
It  lies  about  an  inch  above  the  laryngeal  prominence  and  on 
a  level  with  the  lower  part  of  the  third  cervical  vertebra.  The 
arch  of  the  cricoid  cartilage,  which  lies  i|  inches  below  the 
laryngeal  prominence,  is  placed  opposite  the  sixth  cervical 
vertebra.  If  the  finger  is  thrust  backwards  and  laterally  under 
cover  of  the  anterior  border  of  the  sterno-mastoid  at  this 
level,  the  common  carotid  artery  may  be  compressed  against 
the  anterior  tubercle  of  the  transverse  process  of  the  sixth 
cervical  vertebra — the  carotid  tubercle. 

The  anterior  border  of  the  trapezius  may  be  traced  from  its 
origin  on  the  occipital  bone  downwards,  round  the  side  of  the 
neck,  to  its  insertion  into  the  clavicle. 

The  spine  of  the  seventh  cervical  vertebra  can  be  identified  as  it 
lies  at  the  lower  end  of  the  nuchal  furrow  ;  the  upper  six  cervical 


io8  THE  HEAD  AND  NECK 

spines  lie  at  the  bottom  of  the  nuchal  furrow,  and  are  obscured 
by  the  ligamentum  nuchae. 

The  Platysma. — This  muscular  sheet  lies  in  the  superficial 
fascia  of  the  neck.  Its  anterior  border  runs  obliquely  upwards 
and  medially.  For  a  short  distance  below  the  chin  it  meets 
and  decussates  with  the  corresponding  muscle  of  the  opposite 
side,  but  the  two  muscles  separate  from  one  another  below 
(Fig.  51).  It  is  supplied  on  its  deep  surface  by  the  cervical 
branch  of  the  facial  nerve.  The  platysma  aids  the  facial  muscles 
which  drag  downwards  the  lower  lip  and  the  angle  of  the  mouth. 
Incisions  which  approach  too  near  to  the  angle  of  the  mandible 
(p.  134)  may  cut  the  nerve  to  the  platysma  (and  depressor  labii 
inf.)  and  cause  paralysis  of  the  movements  indicated. 

Superficial  Nerves. — The  skin  of  the  front  and  side  of  the 
neck  is  supplied  by  branches  from  C.  2,  C.  3,  and  C.  4.  The 
nerves  appear  from  under  cover  of  the  sterno-mastoid,  near 
the  middle  of  its  posterior  border,  and  radiate  in  various  direc- 
tions. Like  the  superficial  veins,  they  lie  deep  to  the  platysma. 

The  descending,  supra-clavicular,  branches  (C.  3  and  C.  4) 
are  described  on  p.  4. 

The  ascending  branches  are  the  lesser  occipital  (C.  2),  which 
runs  upwards  along  the  posterior  border  of  the  sterno-mastoid 
to  the  scalp,  and  the  great  auricular  (C.  2  and  3),  which  ascends 
across  the  muscle  superficially,  and  supplies  the  skin  over  the 
angle  of  the  jaw  and  the  postero-inferior  part  of  the  auricle. 
The  great  auricular  nerve  usually  accompanies  the  upper  half 
of  the  external  jugular  vein  (Fig.  35). 

These  nerves  are  commonly  divided  in  operations  for  the 
removal  of  tuberculous  lymph  glands,  and  occasionally  their 
cut  ends  become  adherent  to  the  scar.  Neuralgia,  arising 
from  this  cause,  radiates  over  the  area  supplied  by  the  other 
nerves  which  arise  from  the  same  segment  of  the  spinal  medulla 
as  the  nerve  involved.  The  surgeon  may  resect  the  superficial 
nerves  of  the  neck  as  soon  as  they  are  exposed  as  a  prophylactic 
measure,  and,  although  some  loss  of  sensation  may  result,  the 
condition  gradually  improves. 

Posteriorly,  the  skin  is  supplied  by  the  posterior  rami  (primary 
divisions)  of  the  second  to  the  sixth  cervical  nerves. 

The  line  of  anaesthesia  in  fracture  dislocations  below  the 
fourth  cervical  vertebra  is  described  on  p.  530. 

The  External  Jugular  Vein  is  formed  at  the  lower  border  of 
the  parotid  gland  by  the  union  of  the  posterior  auricular  and  a 


THE  NECK 


109 


branch  (the  posterior  division  of  the  temporo-maxillary)  from 
the  posterior  facial  vein  (Fig.  35).  It  is  visible  as  it  descends 
vertically  across  the  sterno-mastoid  to  the  angle  between  its 
posterior  border  and  the  clavicle,  where  it  enters  the  subclavian 


Auriculo-temporal 
nerve 


Cervical  brand 
of  facial  nerve 
Nervus  cutaneus  coll 


External  jugiil 


Greater  occipital  nerve 
Posterior  auricular  vein 

Third  occipital  nerve 

imencement  of  external  jugular  vein 
Lesser  occipital  nerve 
Great  auricular  nerve 
Nerve  to  levator  scapula; 
Accessory  nerve 

Branches  to  trapezius  from  C.  3  and  4 
Supra-clavicular  nerves 

sverse  cervical  vein 


Oino-hyoid,  post,  belly 
Transverse  scapular  vein 

Connecting  branch 


Cephalic  veil 


FIG.  35. — Superficial  Nerves  and  Veins  of  the  Neck. 

vein  after  piercing  the  deep  fascia.  About  its  mid-point  the 
external  jugular  vein  receives  a  tributary,  which  drains  the 
superficial  tissues  of  the  posterior  aspects  of  the  scalp  and  th^ 
neck.  After  piercing  the  deep  fascia,  it  is  joined  on  its  lateral 
side  by  the  transverse  cervical  and  transverse  scapular  (supra- 
scapular)  veins,  and,  on  its  medial  side,  by  the  anterior  jugular. 


no  THE  HEAD  AND  NECK 

The  vein  wall  is  very  adherent  to  the  margins  of  the  opening 
in  the  deep  fascia  through  which  it  passes,  and  at  this  point, 
therefore,,  the  vein  cannot  collapse.  If  the  vessel  is  cut  in  this 
region  there  is  danger  lest  air  be  drawn  in  by  the  suction  of  the 
chest  in  inspiration,  and  on  this  account  the  finger  should 
immediately  be  applied  over  such  a  wound.  In  its  upper  half 
the  external  jugular  vein  is  commonly  accompanied  by  the  great 
auricular  nerve,  and  throughout  its  whole  course  it  is  closely 
related  to  the  superficial  cervical  lymph  glands. 

Owing  to  its  superficial  position,  the  external  jugular  vein 
may  be  opened  to  relieve  the  venous  congestion  which  sometimes 
occurs  during  the  administration  of  an  anaesthetic  from  disten- 
tion  of  the  right  side  of  the  heart. 

The  Anterior  Jugular  Vein  arises  just  below  the  chin  and 
runs  downwards  near  the  anterior  median  line  of  the  neck  (p.  164). 
It  turns  laterally  deep  to  the  sterno-mastoid,  just  above  the 
clavicle,  and  joins  the  external  jugular  vein  close  to  its  termina- 
tion. Occasionally  the  anterior  jugular  is  joined  by  the  common 
facial  vein.  The  two  anterior  jugular  veins  are  connected  by  a 
transverse  branch  (Fig.  51)  which  lies  in  the  suprasternal  space 
(of  Burns)  (p.  in). 

The  superficial  veins  of  the  neck  vary  considerably  in  size, 
and  the  increase  of  one  is  balanced  by  the  decrease  of  another. 

The  Superficial  Cervical  Lymph  Glands  lie  in  the  superficial 
fascia  of  the  neck.  They  consist  of  three  groups,  (A)  Occipital, 
(B)  Mastoid,  and  (C)  a  chain  of  glands  accompanying  the  external 
jugular  vein. 

A.  The  Occipital  lymph  glands  lie  at  the  apex  of  the  posterior 
triangle.    They  receive  afferents  from  the  posterior  part  of  the 
scalp,  and  are  commonly  enlarged  in  pediculosis  or  impetigo 
of  the  area  which  they  drain.     Their  efferents  pass  partly  to 
group  (C),  and  partly  to  the  upper  posterior  group  of  the  deep 
cervical  lymph  glands  (p.  132). 

B.  The  Mastoid  lymph  glands  lie  on  the  upper  part  of  the 
sterno-mastoid.    They  drain  the  adjoining  area  of  the  scalp 
and  the  deep  surface  of  the  pinna,  and  their  efferents  take  the 
same  course  as  the  efferents  of  the  occipital  glands. 

C.  This  group  receives  afferents  from  the  Occipital  and 
Mastoid  lymph  glands,  which  are  the  usual  sources  of  infection. 
They  are  not  liable  to  tuberculous  disease,  and  therefore,  when 
they  become  enlarged,  there  is  very  little  periadenitis,  so  that 
they  can  easily  be  felt  to  slip  about  beneath  the  platysma. 


THE  NECK  in 

Deep  Cervical  Fascia. — The  deep  fascia  of  the  neck  con- 
sists of  an  investing  layer  and  of  several  subsidiary  processes. 

(a)  The  Investing  Layer  forms  the  roof  of  the  anterior 
triangle,  and  is  firmly  bound  down  to  the  hyoid  bone.    Traced 
laterally,  it  encloses  the  sterno-mastoid,  forms  the  roof  of  the 
posterior  triangle,  and  then  invests  the  trapezius  (Fig.  36).     It 
is  attached  above  to  the  lower  border  of  the  mandible,  but,  in 
the  neighbourhood  of  the  angle,  it  is  carried  upwards,  enclosing 
the  parotid  gland,  to  the  zygomatic  arch  and  the  antero-inferior 
border  of  the  external  acoustic  (auditory)  meatus.     It  is  attached 
to  the  mastoid  process,  the  superior  nuchal  line  of  the  occipital 
bone,  and  the  external  occipital  protuberance,  i.e.  it  corresponds 
to  the  attachments  of  the  sterno-mastoid  and  the  trapezius. 

Between  the  angle  of  the  mandible  and  the  greater  cornu 
of  the  hyoid  bone,  the  investing  layer  blends  with  the  fascial 
sheath  of  the  posterior  belly  of  the  digastric  ;  between  the  chin 
and  the  greater  cornu  a  similar  connection  is  formed  with  the 
fascial  sheath  of  the  anterior  belly  of  the  digastric.  In  this 
way  the  submaxillary  and  submental  regions  are  shut  off  from 
one  another  and  from  the  rest  of  the  neck  (p.  145). 

Just  above  the  jugular  (suprasternal)  notch  the  investing 
layer  splits  into  two  lamellae,  which  are  attached  to  the  front 
and  back  of  the  manubrium  sterni.  The  space  between  them — 
the  suprasternal  space  (of  Burns} — contains  one  or  two  lymph 
glands  and  a  communication  between  the  two  anterior  jugular 
veins  (Fig.  51).  Traced  laterally,  these  two  layers  enclose  the 
sterno-mastoid,  and  pass  down  to  the  clavicle.  In  the  lower 
part  of  the  posterior  triangle  the  same  two  layers  can  again  be 
recognised,  and,  for  about  an  inch  above  the  clavicle,  they  are 
separated  by  some  loose  fat.  The  deeper  layer  encloses  the 
posterior  belly  of  the  omo-hyoid,  and  holds  it  down  in  place ;  the 
superficial  layer,  which  is  very  thin  and  ill-defined,  is  continuous 
with  the  fascia  covering  the  trapezius. 

The  investing  layer  is  much  stronger  over  the  triangles  than 
it  is  over  the  trapezius  and  the  sterno-mastoid.  So  firmly  does 
it  bind  the  structures  together  that,  in  operations  on  the  neck, 
good  exposure  can  be  obtained  only  after  it  has  been  divided 
freely.  In  flap  operations  the  flap  should  consist  of  all  the  tissues 
down  to  and  including  the  deep  cervical  fascia. 

(b)  The  Prevertebral  Fascia  covers  the  muscles  which  are 
closely  applied  to  the  anterior  aspects  of  the  cervical  vertebrae. 
It  is  attached  above  to  the  basi-occiput,  and  it  passes  down  as 


112 


THE  HEAD  AND  NECK 


a  thick  sheet  into  the  thorax,  where  it  blends  with  the  anterior 
longitudinal  (common)  ligament.  Traced  laterally,  the  pre- 
vertebral  fascia  gradually  becomes  thinner.  It  passes  behind 
the  great  vessels  of  the  neck  and  covers  the  muscles  on  which 
they  lie,  viz.  the  longus  colli,  the  longus  capitis  (rectus  capitis 
anticus  major),  and  the  scalenus  anterior.  It  is  then  continued 
on  to  the  surfaces  of  the  adjacent  muscles,  viz.  the  splenius 

Sterno-hyoid    Anterior  jugular  vein,  transverse  anastomosis 
Anterior  jugular  vein     |     |       Trachea 

Recurrent  nerve  I        Suprasternal  space 

Parathyreoid  gland     I  i  Sheath  of  thyreoid  gland 

Investing  layer     |      |    |         |     |     (Ksophagus 

Sterno-thyreoid        v^A-rt3^4-=^ — i^^Zr-/-^       Thyreoid  gland 

Sheath  of  thyreoid  gland      >^^<SJfiSlE3E83s2RSifc5*^,    Capsule  of  thyreoid  gland 
Sterno-mastoid    >^2«Sgi  ^g^l^v  C!t7ugU[ar  «?*"* 

arotid  sheath 

t-ertebral  fascia 


xt.  jugular  vein 
Onio-hyoid 

Investing 

layer  of  deep 

cervical 

fascia 


Sympathetic  trunk        ' 
Inferior  thyreoid  artery 


-ong-  thoracic  nerve  (of  Bel 
Vertebral  vessels 


FIG.  36. — Transverse  Section  through  Neck,  at  level  of  Seventh  Cervical 
Vertebra,  showing  the  arrangement  of  the  Deep  Cervical  Fascia.  On 
the  left  side,  a  tuberculous  abscess  is  shown,  originating  in  the  body  of 
a  vertebra  and  spreading  laterally  behind  the  pre vertebral  fascia.  After 
eroding  the  muscles,  it  has  penetrated  the  prevertebral  fascia  and  made 
its  way  into  the  posterior  triangle  of  the  neck. 


capitis,  the  levator  scapulae,  the  scalenus  medius  and  posterior, 
i.e.  it  forms  the  fascial  floor  of  the  posterior  triangle.  As  the 
anterior  rami  (primary  divisions)  of  the  cervical  nerves  lie  on 
the  upper  surfaces  of  the  transverse  processes  of  the  vertebrae, 
they  are  situated  behind  the  prevertebral  fascia.  The  superficial 
branches  of  the  cervical  plexus  soon  pierce  it,  but  the  phrenic 
nerve  lies  deep  to  the  fascia  as  it  runs  down  in  front  of  the  scalenus 
anterior.  When  the  roots  of  the  brachial  plexus  and  the  sub- 
clavian  artery  emerge  from  under  cover  of  the  scalenus  anterior, 
they  carry  the  prevertebral  fascia  with  them  downwards  and 


THE  NECK  113 

laterally  towards  the  apex  of  the  axilla,  and  so  form  the  axillary 
sheath.  It  will  be  seen  from  Fig.  36  that  the  prevertebral 
fascia,  after  covering  the  floor  of  the  posterior  triangle,  blends 
with  the  fascia  on  the  deep  surface  of  the  trapezius  and  reaches 
the  ligamentum  nuchse.  In  this  way  it  forms  a  complete  layer 

Genio-hyoid 

Sublingual  gland 

-Genio-glossus 
jJ^S 

3\  fT-xV  Mylo-hyoid 


Epiglottis 


Investing  layer 

Lingual  artery 
Submaxillary  gland 
Hyo-glossus 
Palatine  tonsil 

Greater  cornu  of 
hyoid  bone 

Sterno-mastoid 

Carotid  sheath 

Bucco-  pharyngeal 
fascia 

Sympathetic  trunk 

Retro-pharyngeal 
lymph  gland 


SSM*J«.  ^fSf^^     Vertebral  vesse,s 

Retro-pharyngeal 
abscess 

Prevertebral  fascia  Trapezius 

FIG.  37. — Transverse  Section  through  the  Neck  of  a  Child,  at  the  level  of  the 
Third  Cervical  Vertebra,  showing  the  arrangement  of  the  Deep  Cervical 
and  Bucco-pharyngeal  fasciae.  An  abscess  is  shown  in  the  retro- 
pharyngeal  space,  originating  in  one  of  the  lymph  glands  in  that  situation. 
Its  relation  to  the  prevertebral  fascia  should  be  carefully  noted.  Cf. 
Fig.  50. 

around  the  neck,  but  it  lies  on  a  deeper  plane  than  the  investing 
layer. 

Pus  arising  from  tuberculous  disease  of  the  upper  cervical 
vertebrae  lies  behind  the  prevertebral  fascia  (Fig.  36).  It  forms 
a  swelling  on  the  posterior  wall  of  the  pharynx  which  causes 
difficulty  in  swallowing  and  respiration.  Owing  to  the  strength 

8 


ii4  THE  HEAD  AND  NECK 

of  the  fascia  in  the  median  plane,  the  pus  travels  downwards 
and  laterally  behind  the  carotid  sheath  and  reaches  the  posterior 
triangle.  In  this  situation  the  fascia  is  much  weaker,  and  the 
abscess  points  behind  the  sterno-mastoid.  It  is  best  approached 
by  an  incision  along  the  posterior  border  of  the  muscle  (Chiene), 
which  is  then  retracted  forwards  together  with  the  carotid  sheath. 
A  search  is  made  for  the  transverse  processes  of  the  cervical 
vertebrae,,  which  provide  the  deep  landmarks  to  the  site  of  the 
abscess  (p.  520).  Rarely,  the  pus  travels  downwards  behind 
the  prevertebral  fascia  and  enters  the  mediastinal  space.  This 
variety  of  abscess  must  be  distinguished  from  an  abscess  originat- 
ing in  the  lymph  glands  which  occupy  the  interval  between 
the  prevertebral  fascia  and  the  bucco-pharyngeal  fascia  on  the 
outer  surface  of  the  constrictor  muscles  (Fig.  37).  They  drain 
the  naso-pharynx,  and  their  efferents  pass  laterally  to  open 
into  the  upper  group  of  the  deep  cervical  lymph  glands.  An 
abscess  arising  in  connection  with  the  retro -pharyngeal  lymph 
glands  causes  a  swelling  on  the  posterior  wall  of  the  pharynx, 
usually  to  one  or  other  side  of  the  median  plane.  Should  it 
rupture  into  the  pharynx  during  sleep,  it  may  lead  to  suffocation. 
Abscesses  in  front  of  the  prevertebral  fascia  should  be  opened 
from  the  mouth  with  the  patient's  head  inverted  (Rose's  posi- 
tion), but  this  route  is  avoided  in  dealing  with  pus  behind  the 
prevertebral  fascia — which  is  tuberculous  in  origin — on  account 
of  the  danger  of  mixed  infection. 

(c)  The  Pretracheal  Fascia  is  a  much  thinner  sheet  than 
the  prevertebral.     It  lies  in  front  of  the  trachea  and  the  lower 
part  of  the  larynx,  and  forms  a  fascial  sheath  for  the  thyreoid 
gland  (p.   167).     It  is  separated  from  the  prevertebral  fascia 
by  the  oesophagus  and  trachea,  and  from  the  investing  layer  by 
the  depressor  muscles  of  the  hyoid  bone  (Fig.  36).     The  pre- 
tracheal  fascia  covers  the  crico-thyreoid  muscle  and  is  firmly 
adherent  to  the  cricoid  and  thyreoid  cartilages.     It  does  not 
extend  upwards  beyond  the  thyreoid  cartilage  but,  inferiorly, 
it  descends  into  the  superior  mediastinum  and  blends  with  the 
outer  coat  of  the  arch  of  the  aorta.     Laterally,  the  pretracheal 
fascia  blends  with  the  anterior  wall  of  the  carotid  sheath. 

(d)  The  Carotid  Sheath. — The  common  and  internal  carotid 
arteries,  the  internal  jugular  vein,  and  the  vagus  nerve,  are 
surrounded  by  a  tubular  investment  of  the  deep  cervical  fascia. 
The  sheath  is  best  seen  in  relationship  to  the  upper  half  of  the 
common  carotid  artery  :  above  and  below  that  area  it  gradually 


THE  NECK  115 

becomes  indefinite.  The  posterior  wall  of  the  sheath  is  con- 
nected to  the  prevertebral  fascia  by  some  loose  connective  tissue, 
which,  however,  does  not  prevent  pus  from  spreading  laterally 
between  them ;  its  anterior  wall  fuses  with  the  pretracheal 
fascia. 

Relations  of  the  Carotid  Sheath. — The  carotid  sheath  is  so 
frequently  exposed  in  operations  on  the  neck  that  its  relations 
require  careful  consideration.  At  its  lower  end  it  is  covered 
by  the  sterno-hyoid  and  the  sterno-thyreoid  muscles  and,  more 
superficially,  by  the  sternal  head  of  the  sterno-mastoid.  Between 
these  two  muscular  layers  the  anterior  jugular  vein  runs  laterally, 
just  above  the  clavicle,  and  hence  it  runs  the  risk  of  injury  when 
these  muscles  are  separated.  Opposite  the  cricoid  cartilage, 
the  sheath  is  crossed  obliquely  by  the  anterior  belly  of  the 
omo-hyoid  (Fig.  38).  (The  intermediate  tendon  of  the  muscle 
exactly  overlies  the  internal  jugular  vein.)  Above  that  level, 
the  carotid  sheath  is  overlapped  by  the  anterior  border  of  the 
sterno-mastoid,  but,  just  below  the  mandible,  it  appears  partially 
from  under  cover  of  the  muscle.  Above  the  level  of  the  hyoid 
bone  the  great  vessels  pass  deep  to  the  stylo-hyoid  and  the 
posterior  belly  of  the  digastric.  Numerous  tributaries  of  the 
internal  jugular  vein  (p.  118)  cross  the  medial  part  of  the  sheath 
to  reach  their  destination.  Opposite  the  hyoid  bone  the  sheath 
is  crossed  transversely  by  the  hypoglossal  nerve  (p.  124)  and, 
at  the  upper  border  of  the  omo-hyoid,  by  the  branch  from  the 
superior  thyreoid  artery  to  the  sterno-mastoid. 

Posteriorly,  the  sheath  rests  on  the  longus  colli  in  its  lower 
part,  and  it  forms  the  roof  of  the  deep  triangle  of  the  neck  (p.  138). 
Superiorly,  it  lies  on  the  transverse  processes  of  the  cervical 
vertebrse  and  on  the  muscles  which  arise  from  them,  viz.  the 
scalenus  anterior  and  the  longus  capitis  (rectus  cap.  antic,  major). 
The  sheath  extends  laterally  so  as  to  overlap  the  phrenic  nerve 
as  it  lies  on  the  scalenus  anterior. 

On  its  medial  side  the  carotid  sheath  is  closely  applied  to  the 
trachea,  the  oesophagus,  and  the  recurrent  (laryngeal)  nerve ; 
the  posterior  border  of  the  lateral  lobe  of  the  thyreoid  gland  is 
an  intimate  relation  and  may  overlap  the  sheath,  while,  at  a 
higher  level,  the  inferior  and  middle  constrictors  of  the  pharynx 
and  the  thyreo-hyoid  membrane  lie  to  its  medial  side. 

Laterally,  the  sheath  is  related  to  the  deep  surface  of  the 
sterno-mastoid,  save  where  the  depressors  of  the  hyoid  bone 
intervene. 

Sa 


n6  THE  HEAD  AND  NECK 

Within  the  carotid  sheath  lie  the  common  carotid  and  the 
commencement  of  the  internal  carotid  artery,  the  internal  jugular 
vein,  the  vagus  nerve,  and  some  lymph  glands.  The  artery 
is  situated  medially  and  on  a  plane  somewhat  anterior  to  the 
internal  jugular  vein,  but  it  is  overlapped  by  the  vein,  which  is 
considerably  the  larger  of  the  two  vessels.  The  vagus  nerve 
lies  between  and  behind  the  artery  and  the  vein.  The  ramus 
descendens  hypoglossi  (p.  154)  is  embedded  in  the  anterior  aspect 
of  the  sheath. 

(e)  The  Stylo-mandibular  Ligament  connects  the  styloid 
process  to  the  deep  surface  of  the  angle  of  the  mandible.  It 
forms  a  part  of  the  sheath  of  the  parotid  gland,  and  it  separates 
the  parotid  from  the  submaxillary  region. 

The  Sterno-mastoid  Muscle  arises  by  a  sternal  and  a 
clavicular  head,  separated  from  one  another  by  a  triangular 
interval,  in  the  floor  of  which  lies  the  lower  end  of  the  carotid 
sheath.  The  fibres  of  the  muscle  pass  upwards  and  backwards 
to  the  mastoid  process  and  the  superior  nuchal  line  of  the 
occipital  bone.  The  muscle  is  firmly  held  in  place  by  the  deep 
fascia,  and  its  anterior  border  shows  a  forward  convexity 
which  disappears  when  the  fascia  is  incised  along  it,  permitting 
the  carotid  sheath  to  come  into  view.  The  nerve-supply  of  the 
sterno-mastoid  is  derived  from  the  accessory  (spinal  accessory) 
nerve  and  the  anterior  ramus  (primary  division)  of  C.  2.  When 
the  accessory  nerve  is  cut,  the  muscle  of  the  opposite  side,  being 
unopposed,  draws  the  head  down  to  its  own  side,  and  at  the  same 
time  rotates  and  tilts  the  head  so  that  the  chin  is  directed  up- 
wards and  towards  the  affected  side.  In  these  cases,  therefore, 
the  torti-collis  is  found  on  the  other  side  of  the  neck  from  the 
causative  lesion.  Congenital  torti-collis  is  due  to  shortening  of 
the  muscle  of  the  same  side,  either  from  mal-development  or 
from  cicatricial  fibrosis  following  rupture  during  parturition. 

Acquired  torti-collis  may  be  due  to  astigmatism,  or  to  the 
irritation  of  the  second  cervical  nerve  by  Potts'  disease,  or  it  may 
be  caused  by  the  pressure  of  inflamed  lymph  glands  on  the 
accessory  nerve.  This  variety  can  always  be  distinguished  from 
the  true  form  by  the  absence  of  facial  asymmetry. 

In  the  treatment  of  congenital  torti-collis,  subcutaneous 
tenotomy  of  the  sterno-mastoid  near  its  origin  has  fallen  into 
disuse  on  account  of  the  danger  of  wounding  the  anterior  or  the 
external  jugular  vein  (p.  108).  In  addition,  the  deep  cervical 
fascia,  which  is  also  contracted,  must  be  divided  in  order  to 


THE  NECK  117 

ensure  a  successful  result,  and  this  proceeding  cannot  be  carried 
out  by  the  subcutaneous  method.  At  the  present  time  an  open 
operation  is  performed  through  an  oblique  incision  across  the 
lower  part  of  the  muscle.  The  deep  fascia  is  freely  incised,  and 
the  muscle  is  divided  along  with  the  fascia  on  its  deep  surface. 
It  may  even  be  necessary  to  open  the  carotid  sheath  to  obtain 
sufficient  relaxation. 

The  Internal  Jugular  Vein  is  a  direct  downward  con- 
tinuation of  the  transverse  (lateral)  sinus,  and  it  emerges  from  the 
skull  at  the  posterior  part  of  the  jugular  foramen.  In  its  upper- 
most part  it  is  rarely  seen  by  the  surgeon,  since  it  lies  deeply, 
under  cover  of  the  styloid  process  and  the  parotid  gland.  It 
descends  in  the  carotid  sheath,  the  relations  of  which  are 
described  on  p.  115,  and  it  is  covered  by  the  sterno-mastoid 
muscle.  In  the  sheath  the  vein  lies  on  the  lateral  side  of  the 
common  carotid  artery  and  its  terminal  branches,  but  it  overlaps 
them  anteriorly.  When  an  opening  is  made  in  the  carotid 
sheath,  the  vein  bulges  through  and  it  is  easily  recognised  by 
its  blue-grey  colour.  If  the  venous  return  to  the  heart  is  ob- 
structed in  any  way,  the  internal  jugular  vein  shares  in  the  general 
engorgement  and  becomes  greatly  distended.  In  the  lower  part 
of  the  neck  the  vein  crosses  in  front  of  the  first  part  of  the 
subclavian  artery,  and  it  terminates  behind  the  sternal  end  of 
the  clavicle  by  uniting  with  the  subclavian  to  form  the  in- 
nominate vein. 

Malignant  and  tuberculous  lymph  glands  frequently  become 
adherent  to  the  internal  jugular  vein,  and  it  is  not  uncommon 
for  the  surgeon  to  resect  a  portion  of  the  vessel  in  order  to  facilitate 
their  removal.  The  vein  is  first  isolated  inferiorly,  and  it  is 
then  divided  between  ligatures  as  low  down  as  necessary.  The 
vein  is  then  dissected  upwards — a  procedure  which  is  easier 
than  the  reverse  method,  because  numerous  tributaries  join  the 
vein  in  its  upper  part  and  render  its  isolation  extremely  difficult. 
The  portion  most  commonly  resected  receives  the  common  facial 
vein,  which  must  also  be  ligatured  and  divided.  The  rise  in 
pressure  in  the  internal  jugular  vein  during  vomiting  is  so  great 
that  lateral  ligatures  may  be  forced  off.  Consequently,  if  the 
vein  is  wounded  during  an  operation,  it  is  much  safer  to  divide 
it  completely  and  ligature  both  the  cut  ends. 

The  Common  Facial  Vein  is  the  most  important  tributary 
of  the  internal  jugular,  and  it  serves  as  a  useful  landmark  in 
removal  of  the  tonsillar  and  the  upper  anterior  group  of  the 


n8 


THE  HEAD  AND  NECK 


deep  cervical  lymph  glands  (p.  132).  It  is  formed  at  the  lower 
border  of  the  submaxillary  gland  by  the  union  of  the  anterior 
and  posterior  facial  veins  (facial  and  anterior  division  of  temporo- 
maxillary  vein) ;  the  former  drains  the  muscles  and  tissues  of 


Anterior 
auricular  glands 

Occipital  glands 

Anterior  group  of upper^ 
deep  cervical  glands " 
Posterior  group  of  upper 
deep  cervical  glands 


Lower  deep  cervic 
glands,  posterior  group' 


Lower  deep 
cervical  glands, 
anterior  gr 


onsillar  gland 
Submaxillary  salivary 
gland 
^Common  facial  vein 

""Superior  thyreoid  vein 

hyoid 
"~  Internal  jugular  vein 


FIG.  38. — The  Veins  and  Lymph  Glands  of  the  Neck.  The  upper  part  of 
the  external  jugular  vein  has  been  resected.  The  sterno-mastoid  has 
been  cut  across  below  the  point  at  which  it  is  pierced  by  the  accessory 
nerve,  and  the  two  cut  ends  have  been  turned  upwards  and  downwards, 
respectively. 

the  face,  while  the  latter  emerges  from  the  substance  of  the 
parotid  gland.  The  common  facial  vein  passes  backwards  and 
downwards,  superficial  to  the  carotid  sheath,  which  it  pierces 
opposite  the  greater  cornu  of  the  hyoid  bone.  Its  direction  is 
often  altered  by  enlarged  lymph  glands.  Sometimes  it  runs 


THE  NECK  119 

horizontally  backwards,  and  sometimes  almost  vertically  down- 
wards ;  in  the  latter  case  it  may  be  mistaken  for  the  internal 
jugular  vein.  It  usually  receives  the  superior  thyreoid,  lingual, 
and  tonsillitic  veins.  The  last  two  are  found  under  cover  of 
the  posterior  belly  of  the  digastric,  and  often  open  directly  into 
the  internal  jugular  vein.  Not  infrequently  the  common  facial 
ends  by  joining  the  anterior  jugular  vein,  which  is  considerably 
increased  in  size  in  these  cases. 

The  Superior  Thyreoid  Vein  generally  ascends  to  enter  the 
common  facial,  but  it  may  join  the  internal  jugular  directly  by 
crossing  the  common  carotid  artery. 

The  Middle  Thyreoid  Vein,  which  appears  from  under  cover 
of  the  anterior  belly  of  the  omo-hyoid,  enters  the  internal  jugular 
vein  after  piercing  the  anterior  aspect  of  the  carotid  sheath 
(p.  120). 

The  Common  Carotid  Artery.— On  the  right  side,  the 
common  carotid  artery  arises  from  the  innominate  artery  behind 
the  sterno-clavicular  joint ;  on  the  left  side,  it  arises  from  the 
arch  of  the  aorta  and  lies  in  the  superior  mediastinum  for 
ij  inches.  The  course  of  the  artery  in  the  neck  can  be  mapped 
out  by  a  line  drawn  from  the  sterno-clavicular  joint  to  a  point 
midway  between  the  angle  of  the  mandible  and  the  mastoid 
process.  Opposite  the  upper  border  of  the  thyreoid  cartilage, 
which  lies  at  the  level  of  the  fourth  cervical  vertebra, the  common 
carotid  ends  by  dividing  into  the  internal  and  external  carotid 
arteries.  As  it  lies  in  front  of  the  carotid  tubercle  (p.  107), 
the  artery  is  crossed  by  the  anterior  belly  of  the  omo-hyoid, 
which  is  running  upwards,  forwards,  and  medially. 

Ligature  of  the  common  carotid  artery  above  the  omo-hyoid  is 
performed  for  congenital  hydrocephalus  (Stiles),  or  for  aneurism 
of  the  innominate  artery.  Temporary  occlusion  of  the  vessel  by 
Crile's  method  may  be  carried  out  in  this  part  of  its  course  as  a 
preliminary  step  to  extensive  operations  on  the  mouth  or  throat. 
This  proceeding  is  dangerous  in  elderly  people,  since  it  may 
induce  cerebral  softening  (p.  120),  and  in  these  patients  the 
external  carotid  should  be  selected.  The  incision  may  be  made 
along  or  obliquely  across  the  anterior  border  of  the  sterno- 
mastoid.  The  skin,  superficial  fascia,  and  the  platysma  are 
divided,  and  the  investing  layer  of  the  deep  cervical  fascia  is 
cut  through  at  the  anterior  border  of  the  sterno-mastoid,  thus 
allowing  the  muscle  to  be  retracted  to  the  lateral  side.  The 
omo-hyoid,  which  is  now  exposed,  is  an  important  landmark, 

8c 


120  THE  HEAD  AND  NECK 

as  it  indicates  the  proximity  of  the  vessel.  It  is  drawn  down- 
wards and  medially,  bringing  the  middle  thyreoid  veins  into  view, 
and  the  carotid  sheath  is  opened  on  its  medial  side  to  avoid 
injuring  the  internal  jugular  vein. 

Ligature  below  the  omo-hyoid  is  performed  for  aneurism  of  the 
distal  part  of  the  artery.  This  operation  is  more  difficult  than 
the  preceding  one,  because  the  vessel  lies  more  deeply  and  is 
placed  under  cover  of  the  sterno-hyoid  and  sterno-thyreoid 
muscles.  The  incision  extends  somewhat  lower,  and  after 
retracting  the  sterno-mastoid  laterally,  the  surgeon  draws  the 
omo-hyoid  upwards  and  laterally,  and  the  sterno-hyoid  and 
sterno-thyreoid  downwards  and  medially. 

In  both  these  operations  care  must  be  taken  not  to  include 
the  vagus  or  the  sympathetic  trunk  in  the  ligature.  If  the 
sympathetic  is  injured,  unilateral  sweating  of  the  head  and  neck, 
contraction  of  the  pupil,  and  retrogression  of  the  eyeball  will 
occur  on  the  affected  side. 

After  ligature  of  the  common  carotid  the  collateral  circulation 
is  carried  out  by  (i)  the  occipital  anastomosis  ;  (2)  the  thyreoid 
anastomosis  ;  (3)  the  anastomosis  which  is  established  by  the 
branches  of  the  external  carotid  arteries,  lingual,  external 
maxillary  (facial),  etc.  across  the  median  plane. 

1.  In  the  occipital  anastomosis,  the  ascending  branch  of  the 
transverse  cervical  (p.  126),  the  profunda  cervicis  (p.  137),  and 
the  ascending  cervical  (p.  143),  which  are  all  derived  from  the 
subclavian  artery,  anastomose  with  the  descending  and  muscular 
branches  of  the  occipital  artery.    This  anastomosis  takes  place 
on  the  superficial  and  deep  surfaces  of  the  semispinalis  capitis 
(complexus). 

2.  The  thyreoid  anastomosis  occurs  between  the  superior 
and  inferior  thyreoid  arteries  in  and  around  the  thyreoid  gland. 
This  anastomosis  also  establishes  a  connection  between  the 
external  carotid  and  the  subclavian  arteries. 

When  the  common  carotid  artery  is  ligatured,  the  brain 
receives  a  sufficient,  though  diminished,  blood-supply,  owing  to 
the  free  anastomosis  established  by  the  arterial  circle  (of  Willis). 
In  infants  suffering  from  hydrocephalus,  one  common  carotid 
having  been  ligatured,  the  other  may  be  tied  after  a  short 
interval  without  any  deleterious  effects  on  the  nutrition  of  the 
brain  (Stiles),  but  in  adults  the  ligature  of  one  common  carotid 
alone  may  produce  cerebral  softening. 

The  External  Carotid  Artery  begins  opposite  the  upper 


THE  NECK  121 

border  of  the  thyreoid  cartilage  and  ends  in  the  parotid  gland, 
behind  the  neck  of  the  mandible,,  by  dividing  into  the  internal 
maxillary  and  superficial  temporal  arteries.  The  course  of  the 
artery  corresponds  to  a  line  drawn  from  a  little  below  the  tip 
of  the  greater  cornu  of  the  hyoid  bone  to  the  lobule  of  the 
auricle. 

In  ligature  of  this  part  of  the  vessel  the  incision  may  be  made 
in  the  natural  folds  of  the  neck,  either  along  the  anterior  border 
of  the  sterno-mastoid  or  crossing  the  muscle  obliquely.  The 
superficial  coverings  are  divided,  and,  in  the  oblique  incision, 
the  external  jugular  vein  and  the  great  auricular  nerve  (p.  108) 
will  be  exposed  in  the  upper  part  of  the  wound.  The  deep 
fascia  is  cut  along  the  anterior  border  of  the  sterno-mastoid,  and 
the  muscle,  which  overlaps  the  artery,  is  retracted  to  the  lateral 
side.  Numerous  veins  (pharyngeal,  lingual,  and  common  facial) 
cross  the  external  carotid  artery  to  reach  the  internal  jugular 
vein.  They  must  be  secured  before  the  upward  continuation 
of  the  carotid  sheath  is  opened.  Care  must  be  taken  not  to  open 
the  sheath  too  much  to  the  medial  side  lest  the  superior  thyreoid 
artery  be  injured  as  it  descends  medial  to  the  sheath.  The 
vessel  is  ligated  between  the  superior  thyreoid  and  lingual 
branches,  i.e.  a  short  distance  below  the  greater  cornu  of  the 
hyoid  bone.  In  this  operation  there  is  little  danger  of  including 
the  vagus  nerve  in  the  ligature,  since  it  is  a  more  intimate 
relation  of  the  internal  carotid  artery,  which  lies  on  a  deeper 
plane. 

The  upper  part  of  the  external  carotid  artery  disappears 
by  passing  under  cover  of  the  stylo-hyoid  and  the  posterior 
belly  of  the  digastric,  but  before  it  does  so  it  is  crossed  from 
behind  forwards  by  the  hypoglossal  nerve  (Fig.  39).  Throughout 
the  rest  of  its  course  the  artery  lies  deeply,  under  cover  of  the 
parotid  gland,  and  is  rarely  exposed  by  the  surgeon. 

The  Superior  Thyreoid  Artery  arises  from  the  external 
carotid  just  above  the  upper  border  of  the  thyreoid  cartilage, 
and  runs  downwards  and  forwards,  disappearing  under  cover 
of  the  omo-hyoid  and  the  sterno-thyreoid  to  supply  the  thyreoid 
gland  (p.  167).  It  may  be  ligated  near  its  origin  by  an  incision 
similar  to  that  employed  for  ligature  of  the  external  carotid. 
The  superior  cornu  of  the  thyreoid  cartilage  is  the  deep  surgical 
guide  to  the  vessel.  The  branches  are  (i)  the  Superior  Laryngeal 
Artery,  which  pierces  the  thyreo-hyoid  membrane  at  the  posterior 
border  of  the  thyreo-hyoid  muscle,  in  company  with  the  internal 


122  THE  HEAD  AND  NECK 

laryngeal  nerve  (p.  159) ;  (2)  the  Crico-thyreoid  Artery  (p.  162) ; 
and  (3)  a  branch  of  supply  to  the  sterno-mastoid  (p.  115). 

The  Lingual  Artery  (p.  145)  arises  from  the  external  carotid 
opposite  the  greater  cornu  of  the  hyoid  bone.  It  makes  an 
upward  loop,  and  then  passes  deep  to  the  posterior  border  of 
the  hyo-glossus  muscle,  and  gains  the  submaxillary  region. 
This  loop  permits  the  hyoid  bone  to  be  elevated  without 
putting  an  undue  strain  on  the  vessel.  In  ligature  of  the  lingual 
artery,  preparatory  to  removal  of  the  tongue,  the  first  part  of 
the  vessel  is  usually  selected,  as  it  is  then  secured  before  its 
important  branches  to  the  tongue  and  the  palatine  tonsil  are 
given  off.  The  incision  is  practically  the  same  as  for  ligature 
of  the  external  carotid  (p.  121).  The  greater  cornu  of  the  hyoid 
bone  is  the  superficial  guide  to  the  vessel,  and  the  posterior 
belly  of  the  digastric  is  a  convenient  guide  to  the  depth  which 
has  been  reached.  Immediately  below  the  muscle  the  hypo- 
glossal  nerve  (p.  124)  crosses  the  arterial  loop,  and  tributaries  of 
the  internal  jugular  vein  often  obscure  both  the  nerve  and  the 
artery. 

The  External  Maxillary  (Facial)  Artery  arises  from  the 
external  carotid  immediately  above  the  lingual  or  occasionally 
by  a  common  trunk  with  it.  Immediately  after  its  origin  it 
passes  upwards  under  cover  of  the  stylo-hyoid  and  the  posterior 
belly  of  the  digastric  and  enters  the  submaxillary  region  (p.  147). 
The  procedure  already  described  for  ligature  of  the  lingual 
artery  may  be  followed  in  ligating  this  vessel. 

The  Occipital  Artery  arises  from  the  posterior  aspect  of  the 
external  carotid  artery  at  the  same  level  as  the  external  maxillary 
(facial).  It  runs  upwards  and  backwards  along  the  lower  border 
of  the  posterior  belly  of  the  digastric,  and  disappears  under 
cover  of  the  mastoid  process  and  the  muscles  attached  to  it. 
In  the  first  part  of  its  course  it  crosses  superficial  to  the  internal 
jugular  vein  and  the  accessory  nerve.  As  it  crosses  the  latter 
it  gives  off  a  branch  of  supply  to  the  sterno-mastoid,  and  this, 
when  cut,  may  serve  to  indicate  the  proximity  of  the  nerve. 
Close  to  its  origin  the  occipital  artery  is  crossed  by  the  hypo- 
glossal  nerve,  which  descends  along  the  lateral  side  of  the  in- 
ternal carotid  and  bends  sharply  forwards  at  this  point  (Fig.  39). 

The  Accessory  (Spinal  Accessory)  Nerve  leaves  the  skull 
through  the  middle  compartment  of  the  jugular  foramen.  At 
first  it  lies  between  the  internal  carotid  and  the  internal  jugular 
vein.  Opposite  the  transverse  process  of  the  atlas  the  nerve, 


THE  NECK 


123 


crosses  the  vein  and  runs  downwards  and  laterally.  It  is 
crossed  by  the  occipital  artery,  and  i|  inches  below  the  tip  of 
the  mastoid  process  it  pierces  the  sheath  of  the  sterno-mastoid. 


External  maxillary  artery 
External  carotid  artery     |         Ascending  palatine  artery 


Facial  nerve 
Posterior  auricular 


Internal  carotid 
artery 

Accessory  nerve 
Occipital  artery 

Hypoglossal  nerve 

Internal  jugular  vein 

Vagus  nerve 

Common  facial  vein,  cut 

•fer.  descendens  hypoglossi 

Rainus  communicans 

cervicalis 

Great  auricular  nerve 
Common  carotid  artery 


Sterno-mastoid  artery     - 
External  jugular  vein    -- 


Sterno-mastoid, 
clavicular  head 


External  maxillary 
artery 

f     Nerve  to  mylo-hyol 
Mylo-hyoid        fe,an( 
Submaxillary  salivary 
Stylo-hyoid 

Anterior  belly  of  digastric 
o-glossus 

Common  tendon  of  digastric 
ngual  artery 
Hyoid  bone 
Nerve  to  thyreo-hyoid 
Internal  laryngeal  nerve 
Superior  thyreoid  artery 
Thyreo-hyoid  muscle 
Thyreo-hyoid  membrane 
Laryngeal  prominence 

External  laryngeal  nerve 
Omo-hyoid 
Sterno-hyoid 


Anterior  jugular  vein 


FIG.  39. — The  Side  of  the  Neck.     The  anterior  border  of  the  sterno-mastoid 
has  been  retracted  in  order  to  expose  the  underlying  vessels  and  nerves. 

Accompanied  by  a  branch  from  the  occipital  artery,  it  enters 
the  muscle,  which  it  supplies.  Its  subsequent  course  is  de- 
scribed on  p.  125. 

The  Hypoglossal  Nerve  lies  deeply,  under  cover  of  the 


124 


THE  HEAD  AND  NECK 


parotid  gland,  in  the  upper  part  of  its  course,  and  it  descends 
between  the  internal  jugular  vein  and  the  internal  carotid 
artery.  It  appears  at  the  lower  border  of  the  posterior  belly 

of  the  digastric,  and 
bends  forwards  almost 
at  right  angles,  hooking 
round  the  occipital  artery. 
It  crosses  superficial  to 
the  internal  and  external 
carotid  arteries  and  to 
the  loop  formed  by  the 
lingual,  and  it  is  itself 
crossed  by  the  lingual 
veins.  It  runs  forwards, 
a  little  above  the  level 
of  the  hyoid  bone,  and 
disappears  under  cover 
of  the  posterior  belly  of 
the  digastric  (Fig.  39). 
It  reappears  above  the 
common  tendon  of  the 
digastric,  lying  on  the 
hyo-glossus.  On  reach- 
ing the  posterior  border 
of  the  mylo-hyoid,  the 
nerve  enters  the  inter- 
muscular  space  between 
this  muscle  and  the  hyo- 

FlG.  40. — Diagram  to  illustrate  the  Path  of  gloSSUS    (p.  154),    and    SO 

the    Efferent    Fibres    from    the    Central  reacheS    the    muscles     of 

Nervous     System     to    the     Sympathetic  ^                          ,  .  ,    . 

Ganglia.       The    cervical    and    the    upper  the  tongue,  which  it  SUP- 

portion  of  the  thoracic  part   of  the  sym-  plies.      In  the  Superficial 

pathetic  trunk  are  shown.      In  the  cervical  par£  Of  fts  course  it  gives 

region,   grey  rami   communicantes  alone  _.         ,             ,.         ,   * 

are  present,    but  in    the   thoracic  region  ot±   a  descending    branch 

white  rami  communicantes  are  present  in  (p.  154)    and    the    nerve 

addition.      The  posterior  rami    (primary  Qf  supply  to  the  thyreo- 

divisions)    of  the  spinal   nerves   are    not  ,        .  , 


shown  in  the  diagram. 


hyoid. 

The  Sympathetic 
Trunk  in  the  neck  is  embedded  in  the  posterior  wall  of  the 
carotid  sheath,  and  lies  posterior  to  the  common  and  internal 
carotid  arteries  and  medial  to  the  vagus  nerve.  It  possesses 
three  ganglia,  and  these  send  afferent  fibres  to  the  spinal 


THE  NECK  125 

medulla  and  efferent  fibres  to  the  blood-vessels,  sweat-glands, 
etc.,  of  the  head,  neck,  and  upper  limb. 

The  anterior  ramus  (primary  division)  of  each  spinal  nerve 
receives  from  the  sympathetic  a  grey  ramus  communicant,  in 
which  afferent  fibres  are  conveyed  to  the  central  nervous  system. 
Efferent  fibres  from  the  spinal  medulla  to  the  sympathetic  are 
contained  in  white  rami  communicantes ,  which  are  only  present 
in  certain  regions  ;  they  connect  the  anterior  rami  of  T.  i  or 
T.  2 — L.  i  or  L.  2,  and  those  of  S.  2  and  3  or  S.  3  and  4  to  the 
corresponding  sympathetic  ganglia.  As  the  cervical  ganglia 
of  the  sympathetic  trunk  receive  no  white  rami  communicantes, 
the  efferent  fibres  which  they  distribute  leave  the  spinal  medulla 
in  the  highest  white  ramus  communicans,  and  then  ascend 
through  the  sympathetic  trunk  into  the  cervical  region  (Fig.  40). 
They  are,  therefore,  involved  in  complete  transverse  lesions  of 
the  spinal  medulla,  above  the  level  of  the  first  thoracic  segment. 
Such  lesions  are  accompanied  by  paralysis  of  the  dilatator 
pupillae  muscle,  which  is  supplied  by  fibres  which  leave  the 
superior  cervical  ganglion  of  the  sympathetic  trunk  and  enter 
the  skull  with  the  internal  carotid  artery.  As  a  result  of  this 
paralysis,  the  pupil  on  the  affected  side  is  small  and  does  not 
react  to  light. 

The  Posterior  Triangle  of  the  Neck.— The  upper  part 
of  the  posterior  triangle  of  the  neck  is  exposed  during  the  re- 
moval of  the  postero-superior  group  of  the  deep  cervical  lymph 
glands ;  its  lower  part  is  exposed  (i)  in  operations  on  the  postero- 
inferior  group  of  lymph  glands,  (2)  in  operations  on  the  brachial 
plexus,  (3)  in  ligature  of  the  third  part  of  the  subclavian  artery, 
and  (4)  in  the  removal  of  a  cervical  rib.  The  base  of  the  triangle 
is  formed  by  the  middle  third  of  the  clavicle,  and  its  anterior 
and  posterior  boundaries  by  the  posterior  border  of  the  sterno- 
mastoid  and  the  anterior  border  of  the  trapezius  respectively. 
The  layers  of  fascia  which  form  the  roof  and  cover  the  floor  of 
the  triangle  are  described  on  pp.  in,  112.  Between  them  a 
varying  amount  of  loose  fat  is  found,  in  which  lie  the  accessory 
nerve,  the  descending  branches  of  the  cervical  plexus,  and  the 
termination  of  the  external  jugular  vein. 

The  Accessory  Nerve  emerges  from  the  sterno-mastoid 
at  the  junction  of  the  upper  and  middle  thirds  of  its  posterior 
border,  and  runs  obliquely  downwards  and  laterally  across  the 
posterior  triangle.  About  two  inches  above  the  clavicle,  or  on 
a  level  with  the  seventh  cervical  spine,  it  disappears  under  cover 


126  THE  HEAD  AND  NECK 

of  the  anterior  border  of  the  trapezius,  in  which  it  terminates. 
Below,  and  parallel  to  the  accessory  nerve,  the  branches  to  the 
trapezius  from  C.  3  and  C.  4  cross  the  triangle.  In  operations 
in  this  region  they  may  be  mistaken  for  the  accessory  nerve, 
and,  as  it  is  important  that  the  latter  should  be  preserved,  the 
surgeon  may  require  to  nip  the  nerve  with  dissecting  forceps  to 
make  certain  of  its  identity.  In  the  case  of  the  accessory,  the 
upper  fibres  of  the  trapezius  will  contract  and  the  shoulder  will 
be  elevated  (p.  6) ;  in  the  other  case,  the  lower  fibres  of  the 
trapezius  will  respond,  but  the  result  cannot  be  appreciated 
from  in  front.  Both  these  motor  nerves  pass  to  the  deep  surface 
of  the  trapezius,  and  in  this  way  they  can  be  distinguished  from 
the  posterior  supra -clavicular  (supra -acromial)  nerves,  which 
run  superficial  to  the  muscle  (Fig.  35). 

In  its  lower  part  the  space  is  crossed  by  the  posterior  belly 
of  the  omo-hyoid,  which  runs  medially  and  slightly  upwards. 
Laterally,  the  muscle  is  completely  hidden  by  the  clavicle,  but  as 
it  approaches  the  sterno-mastoid  it  rises  to  a  higher  level.  When 
operating  in  this  region  the  surgeon  often  finds  it  convenient 
to  cut  through  the  fascial  sheath  of  the  omo-hyoid  (p.  in)  so 
that  the  muscle  may  be  retracted  upwards.  If  necessary,  it  may 
be  cut  away,  without  any  subsequent  disability. 

The  Transverse  Cervical  Artery  arises  from  the  thyreo- 
cervical  trunk  (thyreoid  axis,  p.  143),  and  runs  laterally,  deep  to 
the  sterno-mastoid,  but  in  front  of  the  prevertebral  fascia  and 
the  scalenus  anterior.  It  then  crosses  the  floor  of  the  posterior 
triangle  under  cover  of  the  posterior  belly  of  the  omo-hyoid. 
In  enlargement  of  the  lymph  glands  in  this  region  the  transverse 
cervical  artery  is  increased  in  size,  and  the  haemorrhage  which 
occurs  during  their  removal  is  due  to  the  division  of  its  branches. 

The  Transverse  Scapular  (Suprascapular)  Artery  has  a 
similar  origin  and  course,  but  it  lies  at  a  lower  level.  It  is  placed 
behind  the  clavicle,  and  crosses  in  front  of  the  subclavian 
artery  and  the  brachial  plexus.  The  veins  which  accompany 
these  arteries  join  the  external  jugular  as  it  lies  in  front  of  the 
third  part  of  the  subclavian  artery  (p.  131). 

Exposure  of  the  lower  part  of  the  Posterior  Triangle. — A 
curvilinear  incision,  extending  downwards  along  the  sterno- 
mastoid  and  laterally  along  the  clavicle,  gives  the  best  view  of 
the  lower  part  of  the  posterior  triangle.  When  the  flap  is  turned 
backwards  the  external  jugular  vein  is  exposed,  near  the  apex 
of  the  wound,  as  it  pierces  the  deep  fascia  (p.  109). 


THE  NECK  127 

In  order  that  the  important  nerves  may  not  be  injured,  the 
loose  fat  which  lies  on  the  floor  of  the  triangle  is  best  removed 
by  the  finger,  covered  with  gauze. 

In  exposing  the  brachial  plexus  after  injuries  by  gunshot 
wounds,  or  in  obstetrical  paralysis,  etc.,  the  sterno-mastoid  is 
drawn  forwards  and  the  scalenus  anterior  is  then  brought  into 
view.  If  there  is  little  scar  tissue  the  nerves  may  be  looked 
for  at  the  lateral  border  of  the  scalenus  anterior,  from  behind 
which  they  emerge.  The  prevertebral  fascia  must  be  incised, 
and  C.  5  is  found  about  an  inch  above  the  posterior  belly  of  the 
omo-hyoid.  But  if  much  scar  tissue  is  present  it  is  easier  and 
safer  to  look  for  the  supra-scapular  nerve  first.  It  will  be  found 
by  blunt  dissection  in  the  angle  between  the  clavicle  and  the 
anterior  border  of  the  trapezius,  and  it  can  then  be  traced  medi- 
ally to  its  origin  from  the  upper  trunk  of  the  plexus,  formed 
by  the  union  of  C.  5  and  C.  6. 

These  nerves  can  be  followed  to  the  point  where  they  emerge 
from  under  cover  of  the  scalenus  anterior,  and  the  lower  nerves 
of  the  plexus  can  then  be  identified.  C.  8  and  T.  i  unite  to  form 
the  lower  trunk  behind  the  scalenus  anterior.  This  nerve  trunk 
generally  lies  just  below  the  omo-hyoid  and  above  the  subclavian 
artery,  but  sometimes  it  is  found  behind  the  artery,  occupying 
the  posterior  part  of  the  subclavian  groove  on  the  upper  surface 
of  the  first  rib. 

An  oblique  incision,  running  from  the  junction  of  the  middle 
and  lower  thirds  of  the  posterior  border  of  the  sterno-mastoid 
to  the  angle  between  the  trapezius  and  the  clavicle,  may  also 
be  used  in  the  exposure  of  the  brachial  plexus.  If  necessary, 
it  may  be  prolonged  across  the  clavicle,  and  the  bone  may  be 
divided  temporarily.  The  external  jugular  vein  is  exposed  and 
ligatured,  and  the  omo-hyoid  is  freed  and  retracted  upwards  or 
downwards. 

If  end  to  end  union  is  found  to  be  impossible  after  excision 
of  the  scar  tissue  in  a  torn  cervical  nerve,  the  proximal  end  of 
the  injured  nerve  may  be  implanted  directly  into  the  next  nerve 
of  the  series. 

Bilateral  Ulnar  Paresis  and  Analgesia  sometimes  supervene  if  a  person, 
who  usually  sleeps  on  one  or  other  side,  falls  asleep  lying  on  his  back.  The 
explanation  is  to  be  found  in  the  close  relationship  between  the  first  thoracic 
nerve  (or  the  lower  trunk)  and  the  first  rib,  for  the  weight  of  the  shoulders 
falling  backwards  is  sufficient  to  cause  pressure  on  the  nerve.  For  a  similar 
reason,  symptoms  resembling  those  produced  by  a  cervical  rib  (p.  100)  may 
occur  in  patients  who  are  restricted  to  a  dorsal  decubitus  after  abdominal 


128  THE  HEAD  AND  NECK 

operations,  or  if  the  arms  have  been  allowed  to  hang  down  unsupported  from 
the  operating  table.  Further,  recent  observations  have  shown  that  symptoms 
ascribed  to  the  presence  of  a  cervical  rib  may  in  reality  be  due  to  the  first 
(thoracic)  rib.  Moreover,  the  first  rib  has  been  partially  removed  in  some 
cases,  with  complete  disappearance  of  the  symptoms. 

Cervical  Rib. — The  ventral  portion  of  the  transverse  process 


FJG.  41. Bilateral  Cervical  Ribs.     Viewed  from  behind.     The  cervical 

ribs  are  considerably  foreshortened. 

of  a  cervical  vertebra  is  homologous  with  a  thoracic  rib,  and  is 
termed  the  costal  element.  In  the  case  of  the  sixth  and  seventh 
cervical  vertebrae  the  costal  elements  frequently  develop  from 
independent  secondary  centres  of  ossification,  and  occasionally 
they  undergo  abnormal  development  so  as  to  form  cervical  ribs. 
The  condition  may  be  unilateral  or  bilateral,  and  varies  from  a 


THE  NECK  129 

simple  exostosis  of  the  costal  element  to  a  fully  formed  rib, 
articulating,  by  complete  joints,  with  the  transverse  process  and 
body  of  the  seventh  cervical  vertebra.  The  ventral  extremity  of 
the  rib  may  reach  the  sternum,  or  it  may  articulate  or  fuse  with 
the  first  thoracic  rib  ;  when  small,  it  may  be  attached  to  the  first 
thoracic  rib  by  a  fibrous  band,  or  it  may  present  a  free  extremity. 
Radiograms,  taken  in  an  antero-posterior  plane,  frequently  fail 
to  show  a  cervical  rib  when  one  is  present,  owing  to  foreshorten- 
ing consequent  on  its  downward  and  forward  direction. 

When  the  rib  is  well  developed,  both  the  subclavian  artery 
and  the  lower  trunk  of  the  brachial  plexus  groove  its  upper  and 
anterior  surface.  In  these  cases  the  artery  occupies  a  higher 
position  than  normal,  and  its  pulsations  are  readily  felt.  The 
diagnosis  of  aneurism  may  suggest  itself,  especially  as  the  radial 
pulse  on  the  affected  side  is  weakened,  but  this  sign  disappears 
when  the  limb  is  elevated.  Very  often  the  rib  is  too  short  to  sup- 
port the  artery,  and  is  crossed  by  the  nerve  trunk  only.  Even 
in  these  cases  the  artery  lies  at  a  higher  level  than  normal. 

Muscular  attachments  are  determined  by  the  size  of  the  rib. 
When  it  is  complete,  or  nearly  so,  it  receives  the  insertions  of 
the  scalenus  anterior  and  the  scalenus  medius,  and  intercostal 
muscles  occupy  the  space  between  it  and  the  first  thoracic  rib. 

A  cervical  rib  may  be  present  without  causing  any  symptoms. 
Frequently,  however,  the  pressure  on  the  lower  trunk  of  the 
brachial  plexus  is  such  that  the  removal  of  the  rib  must  be  under- 
taken. The  nervous  symptoms  are  described  on  p.  100. 

Removal  of  a  Cervical  Rib. — In  this  operation  it  is  important 
that  the  whole  area  should  be  widely  exposed.  This  can  be 
effected  by  a  curvi-linear  incision  passing  down  the  posterior 
border  of  the  sterno-mastoid  and  turning  laterally  along  the 
clavicle.  The  external  jugular  vein  is  secured  as  it  pierces  the 
deep  fascia,  and  the  posterior  belly  of  the  omo-hyoid  is  removed. 
The  fat  and  lymph  glands  which  lie  on  the  floor  of  the  posterior 
triangle  are  dissected  away,  and  the  prevertebral  fascia  is 
exposed.  At  this  stage  the  dorsalis  scapulae  nerve  (to  the 
rhomboids)  and  the  long  thoracic  nerve  (of  Bell)  (p.  131)  are 
secured  and  traced  up  to  their  point  of  exit  from  the  scalenus 
medius.  They  are  then  retracted  to  one  or  other  side,  and  the 
lateral  or  posterior  border  of  the  scalenus  medius  is  defined.  The 
rest  of  the  operation  is  carried  out  behind  the  muscle,  and  in 
this  way  the  brachial  plexus  and  the  subclavian  artery,  which 
are  displaced  forwards,  need  not  be  exposed.  The  scalenus 


130  THE  HEAD  AND  NECK 

medius  is  next  separated  from  the  upper  surface  of  the  rib  in  a 
forward  direction,  and  the  bone  is  divided  as  close  to  its  proximal 
extremity  as  possible.  The  distal  portion  is  drawn  laterally, 
and  separated  from  the  intercostal  muscles.  It  is  then  traced 
forwards  as  far  as  possible  and  again  divided. 

The  same  method  may  be  adopted  in  the  removal  of  a  first 
thoracic  rib,  if  it  is  producing  pressure  symptoms,  but  great  care 
must  be  exercised  to  avoid  injuring  the  pleura. 

The  Muscular  Floor  of  the  Posterior  Triangle  is  formed  in 
its  upper  part  by  the  splenius  capitis,  the  fibres  of  which  pass 
forwards  and  upwards  from  the  vertebral  spines  and  ascend 
under  cover  of  the  upper  part  of  the  sterno-mastoid  to  reach 
the  mastoid  process.  Below  and  parallel  to  the  splenius  capitis, 
the  levator  scapula  (Fig.  42)  runs  downwards  and  laterally  from 
the  transverse  processes  of  the  upper  cervical  vertebrae  to  reach 
the  medial  (superior)  angle  of  the  scapula.  At  a  lower  level 
the  scalenus  medius  and  posterior  form  the  floor  of  the  triangle. 
They  are  usually  more  or  less  blended  with  one  another,  and 
their  fibres  have  a  more  downward  inclination,  as  they  are  in- 
serted into  the  posterior  portions  of  the  first  and  second  ribs  re- 
spectively. In  their  lower  part  they  are  crossed  by  the  trunks 
of  the  brachial  plexus  and  the  subclavian  artery. 

The  Scalenus  Anterior  is  usually  completely  under  cover 
of  the  posterior  border  of  the  sterno-mastoid,  but  it  is  exposed 
when  that  muscle  is  retracted  medially.  It  arises  from  the 
anterior  tubercles  of  the  transverse  processes  of  the  intermediate 
cervical  vertebrae,  and  runs  downwards  and  slightly  laterally, 
to  be  inserted  into  the  scalene  tubercle  on  the  inner  margin  of 
the  first  rib.  Like  the  muscles  in  the  floor  of  the  posterior 
triangle,  it  lies  behind  the  prevertebral  fascia,  by  which  it  is 
separated  from  the  posterior  belly  of  the  omo-hyoid. 

The  Phrenic  Nerve  arises  mainly  from  C.  4,  but  it  usually 
receives  additional  fibres  from  C.  3  and  €.5.  It  runs  vertically 
downwards  in  front  of  the  scalenus  anterior  but  behind  the 
prevertebral  fascia,  and  it  is  overlapped  by  the  internal  jugular 
vein.  Owing  to  the  obliquity  of  the  muscle,  the  phrenic  nerve 
crosses  the  scalenus  anterior  from  its  lateral  to  its  medial  border 

(Fig-  44). 

The  nerves  of  supply  to  the  levator  scapulae  and  the  scalene 
muscles  all  lie  deep  to  the  prevertebral  fascia  (p.  112). 

The  Dorsalis  Scapulae  Nerve  (N.  to  the  Rhomboids)  arises 
from  C.  5,  as  it  lies  between  the  scalenus  anterior  and  medius, 


THE  NECK  131 

and  passes  backwards  through  the  scalenus  medius,  emerging 
on  its  lateral  surface,  under  cover  of  the  posterior  belly  of  the 
omo-hyoid.  It  disappears  by  passing  between  the  levator 
scapulae  and  the  scalenus  posterior. 

The  Long  Thoracic  Nerve  (of  Bell)  arises  by  three  roots, 
from  C.  5,  6,  and  7.  The  first  root  arises  in  common  with  the 
dorsalis  scapulae  nerve,  but  separates  from  it  in  the  scalenus 
medius  and  appears  on  the  surface  of  the  muscle  at  a  slightly 
lower  level.  The  second  root  also  pierces  the  scalenus  medius, 
and  unites  with  the  first  to  form  a  common  trunk,  which  runs 
downwards  to  the  axilla  behind  the  main  part  of  the  plexus. 
The  root  from  C.  7  arises  near  the  lateral  border  of  the  scalenus 
medius,  and  enters  the  axilla  before  uniting  with  the  rest  of  the 
nerve. 

Both  the  dorsalis  scapula  and  the  long  thoracic  nerves  lie  behind 
the  prevertebral  fascia,  and,  in  removal  of  the  poster  o-inferior  group 
of  the  deep  cervical  lymph  glands,  they  are  in  no  danger  so  long  as 
the  fascia  is  not  disturbed.  In  operations  in  which  the  pre- 
vertebral  fascia  requires  to  be  opened,  e.g.  repair  of  brachial 
plexus,  these  two  nerves  should  be  found  and  isolated  as  soon 
as  the  fascia  is  incised. 

The  Third  Part  of  the  Subclavian  Artery  commences 
at  the  lateral  border  of  the  scalenus  anterior,  and  extends  down- 
wards and  laterally  to  the  outer  border  of  the  first  rib.  Near 
its  termination,  the  artery  lies  completely  behind  the  clavicle. 
If  pressure  is  exerted  in  a  downward,  medial,  and  backward 
direction  in  the  angle  between  the  posterior  border  of  the  sterno- 
mastoid  and  the  clavicle,  the  subclavian  artery  can  be  compressed 
against  the  first  rib. 

In  making  the  incision  for  the  purpose  of  ligaturing  this  part 
of  the  subclavian  artery,  the  surgeon  draws  the  skin  down  over 
the  clavicle  and  incises  it  along  the  bone.  When  the  skin  is 
allowed  to  retract  upwards,  the  deep  fascia,  which  cannot  be 
drawn  down  with  it,  is  found  exposed  but  not  incised,  and 
therefore  there  is  no  risk  of  injury  to  the  underlying  veins  in 
making  the  incision.  After  division  of  the  deep  fascia,  the 
external  jugular  vein  is  found  as  it  crosses  the  artery  to 
join  the  subclavian  vein.  It  receives  the  transverse  cervical 
and  transverse  scapular  (supra-scapular)  veins  from  the  lateral 
side,  and  these  vessels,  though  often  very  large,  must  not  be 
mistaken  for  the  subclavian  vein,  which  lies  at  a  lower  level 
and  is  under  cover  of  the  clavicle.  The  posterior  belly  of  the 


132  THE  HEAD  AND  NECK 

omo-hyoid  is  freed  and  retracted  upwards,  and  the  veins.,  re- 
ferred to  above,  are  ligatured.  In  this  process  the  transverse 
scapular  (supra-scapular)  artery  (p.  126)  is  exposed  and  pulled 
aside.  The  brachial  plexus  lies  above  and  to  the  lateral  side  of 
the  subclavian  artery,  and  especial  care  must  be  taken  to  avoid 
injuring  the  lower  trunk,  which  frequently  lies  behind  the  vessel. 
By  retracting  the  sterno-mastoid  medially,  the  lateral  border 
of  the  scalenus  anterior,  which  forms  an  important  landmark, 
is  brought  into  view.  If  the  finger  is  carried  downwards  along 
this  border  till  the  tip  rests  on  the  scalene  tubercle,  the  pulp  of 
the  finger  can  feel  the  pulsations  of  the  artery.  As  the  ligature 
is  applied  close  to  the  lateral  border  of  the  scalenus  anterior, 
great  care  must  be  taken  lest  the  pleura,  which  lies  behind  the 
second  part  of  the  artery,  be  damaged. 

In  Interscapulo-Thoracic  Amputation  the  clavicle  is  divided, 
or  its  middle  third  is  resected  and  the  subclavius  muscle  is 
removed.  This  enables  the  surgeon  to  ligate  the  subclavian 
artery  and  vein  and  to  cocainise  the  trunks  of  the  brachial  plexus. 

The  Deep  Cervical  Lymph  Glands  lie  mainly  under  cover 
of  the  sterno-mastoid,  but  they  project  partly  into  the  anterior 
and  partly  into  the  posterior  triangle.  They  can  be  subdivided 
into  four  groups,  upper  and  lower  posterior  and  upper  and  lower 
anterior  (Stiles). 

1.  The  Upper  Posterior  Group  lies  on  the  roots  of  the 
cervical  plexus  and  extends  into  the  posterior  triangle.    They 
receive  afferents  from  the  pharynx,  the  occipital,  and  the  mastoid 
lymph  glands,  and  from  the  upper  anterior  group.    When  these 
glands  are  enlarged,  the  accessory  nerve  may  be  found  embedded 
in  their  midst,  or  lying  immediately  under  the  investing  layer 
of  the  deep  cervical  fascia,  on  the  surface  of  the  glandular  mass. 

2.  The  Lower  Posterior  Group  lies  in  relation  to  the  posterior 
belly  of  the  omo-hyoid  and  superficial  to  the  prevertebral  fascia. 
They  may  be  involved  alone  in  ascending  infection  from  the 
axillary  glands,  as  in  malignant  disease,  or  they  may  be  attacked 
by  a  descending  infection  from  the  upper  groups,  or  by  a  lateral 
spread  from  the  lower  anterior  group. 

3.  The  Upper  Anterior  Group  is  situated  around  the  upper 
part  of  the  carotid  sheath,  but  a  few  of  the  glands  lie  within  the 
sheath  in  close  contact  with  the  internal  jugular  vein.    They 
receive  afferents  from  the  interior  of  the  cranium,  the  pharynx, 
mouth,  nose,  upper  part  of  larynx,  etc.,  either  directly,  or  in- 
directly from  the  submental  and  submaxillary  lymph  glands. 


THE  NECK 


133 


The  tonsillar  lymph  gland  is  placed  in  the  angle  between  the 
common  facial  and  the  internal  jugular  veins.  It  is  very  con- 
stant in  position,  and  is  very  early  involved  in  tuberculous 


Anterior^ 
auricular  gland 

Occipital  gland 

Anterior  group  of  uppe 
deep  cervical  gland 
Posterior  group  of  uppe  _ 
deep  cervical  glands' 


Lower  deep  cervical 
glands,  posterior  gr 


Lower  deep 
cervical  glands, 
anterior  gr 


isillar  gland 

ubmaxillary  salivary 
gland 
vCommon  facial  vein 

•Superior  thyreoid  vein 
•Omo-hyoid 

'*  Internal  jugular  vein 
Sterno-hyoid 


FIG.  42. — The  Veins  and  Lymph  Glands  of  the  Neck.  The  upper  part  of 
the  external  jugular  vein  has  been  resected.  The  sterno-mastoid  has 
been  cut  across  below  the  point  at  which  it  is  pierced  by  the  accessory 
nerve,  and  the  two  cut  ends  have  been  turned  upwards  and  downwards, 
respectively. 

disease  (p.  189).     It  receives  afferents  directly  from  the  palatine 
tonsil. 

4.  The  Lower  Anterior  Group  lies  in  relation  to  the  lower 
part  of  the  carotid  sheath  and  the  scalenus  anterior.  Some  of 
the  members  of  this  group  are  placed  within  the  sheath  ;  others 
lie  between  the  scalenus  anterior  and  the  cervical  pleura ;  and 

9a 


134  THE  HEAD  AND  NECK 

the  remainder  are  in  contact  with  the  anterior  surface  of  the 
muscle.  They  may  be  infected  secondarily  to  the  upper  anterior 
and  lower  posterior  groups,  or  they  may  be  alone  involved 
following  ascending  infection  from  the  mediastinal  lymph 
glands. 

Surgical  Approach  to  the  Deep  Cervical  Lymph 
Glands. — If,  when  the  upper  group  is  involved,  the  enlarged 
lymph  glands  do  not-  extend  into  the  posterior  triangle,  an 
oblique  incision  running  downwards  and  forwards  in  the  skin 
creases  of  the  neck,  towards  the  laryngeal  prominence,,  may 
be  utilised.  It  should  not  approach  nearer  than  one  finger's 
breadth  to  the  angle  of  the  mandible,  lest  the  cervical  branch 
of  the  facial  nerve  be  cut,  with  subsequent  paralysis  of  the 
muscles  of  the  lower  lip  (p.  108). 

If  the  enlarged  glands  extend  far  into  the  posterior  triangle 
an  inverted  ^-shaped  incision  (Stiles)  gives  the  best  access. 
Starting  near  the  greater  cornu  of  the  hyoid,  it  passes  obliquely 
upwards  towards  the  mastoid  process  and  is  then  carried  down- 
wards along  the  anterior  border  of  the  trapezius.  The  latter 
part  of  the  incision  may  be  carried  as  far  as  the  clavicle,  if 
necessary,  and,  as  it  passes  through  the  investing  layer  of  the 
deep  cervical  fascia,  care  must  be  taken  to  avoid  injuring  the 
accessory  nerve  (p.  125). 

In  both  cases  the  external  jugular  vein  is  liable  to  injury.  It 
is  exposed  when  the  margins  of  the  oblique  incision  are  undercut, 
or  when  the  curved  flap,  which  includes  the  platysma,  is  turned 
downwards.  It  is  advisable  to  secure  the  vein  at  once,  as  high 
up  and  as  low  down  as  possible.  The  intervening  portion  can 
then  be  removed,  usually  together  with  the  great  auricular  nerve 
(p.  108).  Excessive  bleeding  at  this  stage  is  suggestive  of 
glandular  pressure  on  the  internal  jugular  vein,  with  consequent 
engorgement  of  the  collateral  channels  of  venous  return.  In  the 
subsequent  stages  of  the  operation  the  structures  most  liable 
to  injury  are  the  internal  jugular  vein  and  the  accessory  nerve. 
They  are  therefore  identified  as  soon  as  the  skin  flaps,  along 
with  the  investing  layer  of  the  deep  fascia,  have  been  under- 
mined and  retracted.  In  tuberculous  lymph-adenitis  the  caseous 
glands  are  commonly  adherent  to  the  carotid  sheath,  and  this 
structure  should  be  opened  below  the  diseased  area.  The 
internal  jugular  vein  can  then  be  dissected  free  without  injury, 
while  the  caseous  glands  and  the  adherent  sheath  can  be  re- 
moved. In  malignant  disease,  however,  the  vein  and  sometimes 


THE  NECK  135 

the  artery  have  to  be  sacrificed.  When  ligatures  are  being 
applied,  prior  to  resection,  care  must  be  taken  not  to  include 
the  vagus  nerve.  Should  the  common  facial  vein  be  wounded 
near  its  termination,  the  haemorrhage  may  be  so  great,  owing 
to  its  proximity  to  the  internal  jugular,  as  to  suggest  injury  of 
the  larger  vessel.  In  ligation  of  the  common  facial,  the  ligatures 
must  be  placed  so  as  to  control  its  numerous  tributaries  (superior 
thyreoid,  etc.,  p.  119). 

The  accessory  nerve  is  found  in  the  upper  part  of  its 
course  by  dissecting  the  deep  fascia  off  the  anterior  border 
of  the  sterno  -  mastoid,  i  J  inches  below  the  tip  of  the 
mastoid  process.  It  pierces  this  fascia  to  reach  the  muscle. 
The  branch  from  the  occipital  artery  to  the  sterno-mastoid 
(p.  122)  serves  as  a  convenient  guide,  and,  after  the  nerve  has 
been  found  in  this  situation,  it  is  traced  upwards  and  forwards 
through  the  glands  till  it  disappears  under  cover  of  the  posterior 
belly  of  the  digastric  (p.  122).  Improved  access  to  the  highest 
group  of  lymph  glands,  which  lie  under  cover  of  the  parotid 
gland  and  the  mastoid  process,  may  be  obtained  by  dividing 
the  anterior  part  of  the  insertion  of  the  sterno-mastoid  trans- 
versely. These  lymph  glands  lie  superficial  to,  and  slightly 
lower  than,  the  occipital  artery. 

The  position  of  the  accessory  nerve  in  the  posterior  triangle 
of  the  neck  is  described  on  p.  125.  When  the  lymph  glands  of 
the  posterior  triangle  are  involved,  the  nerve  must  be  exposed 
before  they  are  attacked,  as  it  is  the  most  important  structure 
in  the  region.  If  a  little  dissection  amongst  the  enlarged  glands 
at  the  middle  of  the  posterior  border  of  the  sterno-mastoid 
fails  to  expose  the  nerve,  it  must  be  sought  for  at  the  point  where 
it  disappears  under  cover  of  the  trapezius  (p.  125),  and  then 
traced  upwards  through  the  mass.  The  enlarged  glands  are  apt 
to  alter  the  course  of  the  nerve,  and  it  runs  grave  risk  of  injury 
if  a  prolonged  search  for  it  is  made  amongst  them. 

When  the  lower  groups  are  involved,  good  exposure  is  obtained 
by  a  long  oblique  incision  extending  from  the  junction  of  the 
middle  and  lower  thirds  of  the  anterior  border  of  the  trapezius 
almost  to  the  jugular  (suprasternal)  notch.  The  terminal  part 
of  the  external  jugular  vein  and  the  accessory  nerve  are  exposed, 
— the  latter  as  it  disappears  under  cover  of  the  trapezius  in  the 
posterior  part  of  the  wound.  In  removing  the  glands,  the 
surgeon  does  not  require  to  cut  through  the  prevertebral  fascia, 
and,  as  a  result,  the  nerves  of  supply  to  the  levator  scapulae 

96 


136  THE  HEAD  AND  NECK 

and  the  rhomboids,,  the  phrenic  nerve  and  the  long  thoracic 
nerve  (of  Bell) — which  all  lie  behind  the  fascial  sheet — are 
perfectly  safe.  When  the  glands  are  being  dissected  from  under 
the  posterior  belly  of  the  omo-hyoid,  haemorrhage  may  occur 
from  the  enlarged  branches  of  the  transverse  cervical  artery 
which  supply  them. 

The  removal  of  the  lower  anterior  group  of  lymph  glands  is 
fully  described  on  p.  141. 

When  all  the  deep  cervical  lymph  glands  are  involved,  the  large 
inverted  J -shaped  incision  (p.  134)  may  be  utilised,  or  it  may 
be  converted  into  an  inverted  U.  This  operation  is  greatly 
simplified  by  dividing  the  sterno-mastoid  transversely  below 
the  level  of  the  accessory  nerve  and  turning  the  cut  ends  upwards 
and  downwards.  The  internal  jugular  vein  and  the  accessory 
nerve  are  satisfactorily  exposed  by  this  procedure.  Behind  the 
prevertebral  fascia,  the  ascending  cervical  artery,  which  is  a 
branch  of  the  inferior  thyreoid,  runs  upwards  in  front  of  the 
scalenus  anterior  on  the  medial  side  of  the  phrenic  nerve  and 
gives  numerous  branches  to  the  deep  cervical  lymph  glands. 

Posterior  Aspect  of  Neck.— This  region  of  the  neck  is 
exposed  by  the  surgeon  in  the  operation  for  the  division  of  the 
posterior  rami  (primary  divisions)  of  the  cervical  nerves,  a 
proceeding  which  is  called  for  in  certain  cases  of  Spasmodic 
Torti-collis.  A  vertical  incision  is  made  from  a  point  midway 
between  the  mastoid  process  and  the  external  occipital  protuber- 
ance downwards  to  the  level  of  the  superior  border  of  the  scapula. 
The  line  of  this  incision  overlies  the  posterior  triangle  of  the 
neck  above  and  the  trapezius  below.  After  the  skin  and  fasciae 
have  been  incised  and  undercut  on  each  side,  the  splenius  is 
exposed  in  the  upper  part  of  the  wound  and  can  be  recognised 
by  the  direction  of  its  fibres,  which  run  upwards  and  laterally. 
In  the  lower  part  of  the  wound  the  splenius  is  covered  over  by 
the  trapezius.  The  latter  muscle  is  cut  through  in  the  line  of 
the  original  incision  and  dissected  off  the  surface  of  the  lower 
part  of  the  splenius.  The  whole  of  the  splenius  is  next  divided 
in  the  same  line,  and  the  two  parts  of  the  muscle  are  undermined 
and  retracted.  The  longissimus  capitis  (trachelo  -  mastoid), 
which  is  a  thin  muscular  sheet  closely  applied  to  the  deep  surface 
of  the  splenius,  is  usually  retracted  along  with  the  lateral  part 
of  the  muscle.  When  this  is  the  case,  the  vertical  fibres  of  the 
semispinalis  capitis  (complexus)  are  completely  exposed,  with 
the  superficial  branches  of  the  ramus  descendens  of  the  occipital 


THE -NECK 


137 


artery  and  their  venae  comites  on  its  surface.  The  semispinalis 
capitis  is  split  along  the  whole  length  of  the  incision,  and  the  two 
parts  are  undermined  and  retracted.  The  deep  branch  of  the 
ramus  descendens  and  the  numerous  veins  which  accompany 


Inferior 


3rd  and  4th  cervical  nerves 
posterior  rain 


Semispinalis  cer 


Superior  oblique 
Rectus  capitis 
posterior  major 
ist  cervical  nerve, 
posterior  ramus 
Communication 
between  ist  and 
2nd  cervical  nerves 
Greater  occipital 
nerve 

.    Articular  process 


_  _  .  Semispinalis  capitis 

Longissimus 

capitis 

Splenius 


_  f Trapezius 


FIG.  43.- 


-Exposure  of  the  Posterior  Ranii  (Primary  Divisions)  of  the 
Upper  Cervical  Nerves. 


it  should  now  be  secured.  They  are  found  running  downwards 
on  the  deep  surface  of  the  semispinalis  capitis  (complexus),  and 
the  arteria  profunda  cervicis,  which  ascends  between  the  same 
muscular  layers  to  anastomose  with  the  ramus  descendens 
(p.  120),  may  also  be  controlled  at  this  stage.  The  semispinalis 
cervicis  (colli)  is  now  exposed  in  the  lower  part  of  the  wound , 


138  THE  HEAD  AND  NECK 

and  its  fibres  can  be  seen  extending  upwards  to  the  spine  of  the 
second  cervical  vertebra.  Along  its  lateral  border  the  articular 
processes  of  the  cervical  vertebrae  can  be  made  out,  while  the 
muscular  sub-occipital  triangle  is  exposed  in  the  upper  part  of 
the  incision  (Fig.  43). 

The  lower  boundary  of  the  sub-occipital  triangle  is  formed  by  the  inferior 
oblique,  which  extends  from  the  spine  of  the  second  cervical  vertebra  to  the 
transverse  process  of  the  atlas.  The  medial  boundary,  formed  by  the  rectus 
capitis  posterior  major,  extends  from  the  spine  of  the  second  cervical  vertebra 
upwards  to  the  occipital  bone  ;  and  the  lateral  boundary,  formed  by  the 
superior  oblique,  ascends  from  the  transverse  process  of  the  atlas  to  the 
occipital  bone.  The  floor  of  the  triangle  is  formed  by  the  posterior  arch  of 
the  atlas  and  the  posterior  atlanto-occipital  membrane  (ligament).  The 
vertebral  artery  lies  on  the  lateral  part  of  the  floor.  After  leaving  the  fora- 
men in  the  transverse  process  of  the  atlas,  it  bends  round  the  posterior  aspect 
of  the  lateral  mass  prior  to  piercing  the  posterior  atlanto-occipital  membrane 
and  the  dura  mater.  In  this  part  of  its  course  the  artery  is  separated  from 
the  posterior  arch  of  the  atlas  by  the  posterior  ramus  (primary  division)  of 
the  first  cervical  nerve,  which  at  once  breaks  up  into  small  branches  to 
supply  the  surrounding  muscles. 

The  most  important  landmark  at  this  stage  is  the  greater 
occipital  nerve.  It  emerges  at  the  lower  border  of  the  inferior 
oblique  and  at  once  turns  upwards  and  medially  into  the  re- 
tracted flap  (Fig.  43).  At  the  lower  border  of  the  inferior 
oblique  the  greater  occipital  nerve  gives  off  a  communicating 
branch,  which  enters  the  sub-occipital  triangle  and  joins  the 
first  cervical  nerve.  It  is  essential  that  this  branch  should  be 
found  and  traced,  as  in  this  way  the  first  cervical  nerve  can  be 
found  with  a  minimum  of  risk  to  the  vertebral  artery.  The 
first  cervical  and  the  greater  occipital  nerves — the  latter  repre- 
sents the  posterior  ramus  (primary  division)  of  C.  2 — are  cut  away 
as  close  to  their  origins  as  possible. 

The  lower  nerves  are  embedded  in  the  fascia  which  separates 
the  semispinalis  capitis  (complexus)  from  the  semispinalis 
cervicis.  If  this  fascia  is  left  behind  when  the  former  muscle 
is  undermined,  the  nerves  will  be  found  on  the  surface  of  the 
latter  (Fig.  43) ;  if  not,  they  will  be  found  on  the  deep  surface 
of  the  semispinalis  capitis.  They  should  be  traced  to  the 
lateral  border  of  the  semispinalis  capitis  and  there  cut  away, 
close  to  the  articular  processes. 

The  Deep  Triangle  of  the  Neck  is  a  well-defined  region 
which  is  of  great  importance  to  the  surgeon,  more  especially 
on  the  left  side.  It  lies  behind  the  lower  part  of  the  carotid 
sheath  and  is  bounded  medially  by  the  longus  colli  and  laterally 
by  the  scalenus  anterior.  The  two  muscles  converge  above 


THE  NECK  139 

on  the  transverse  process  of  the  sixth  cervical  vertebra  to  form 
the  apex  of  the  triangle,  while,  inferiorly,  the  space  is  bounded 
by  the  first  part  of  the  subclavian  artery.  The  surgeon  deals 
with  this  region  (i)  in  operations  for  ligature  of  the  vertebral 
artery,  (2)  in  cesophagotomy,  (3)  in  excision  of  cesophageal 
diverticula,  and  (4)  in  the  removal  of  the  lower  anterior  group 
of  the  deep  cervical  lymph  glands. 

In  the  first  three  operations  mentioned,  access  is  obtained 
by  an  incision  along  the  anterior  border  of  the  sterno-mastoid. 
After  the  investing  layer  of  the  deep  cervical  fascia  has  been  cut 
through,  the  muscle  is  retracted  to  the  lateral  side,  or  its  sternal 
head  may  be  divided.  The  sterno-hyoid  and  sterno-thyreoid 
muscles  are  retracted  medially  and  the  pretracheal  fascia  is 
incised  to  the  medial  side  of  the  carotid  sheath,  which  is  then 
retracted  laterally.  In  this  way  the  posterior  part  of  the  lateral 
lobe  of  the  thyreoid  gland  is  exposed  behind  the  margin  of  the 
sterno-thyreoid.  The  subsequent  procedure  differs  in  the 
various  operations. 

(a)  (Esophagotomy. — The    oesophagus    projects    slightly    to 
the  left  side  from  behind  the  trachea.    In  the  groove  between 
them,  the  left  recurrent  (laryngeal)  nerve  passes  upwards  to 
disappear  at  the  lower  border  of  the  inferior  constrictor,  and  the 
descending  limb  of  the  inferior  thyreoid  artery  (Fig.  44)  runs 
downwards  to  reach  the  lower  pole  of  the  thyreoid  gland.    The 
muscular  wall   of    the  oesophagus  may   be  fully  exposed   by 
retracting  the  trachea,  the  thyreoid  gland,  and  the  depressor 
muscles  of  the  hyoid  bone,  to  the  right.     Posteriorly,  the  oeso- 
phagus rests  on  the  longus  colli,  in  a  layer  of  loose  cellular  tissue, 
but  it  can  easily  be  freed  from  the  muscle  and  raised  to  the 
surface.    The  mucous  and  submucous  coats  of  the  oesophagus 
are  only  attached  to  the  muscular  coat  by  loose  areolar  tissue, 
and  hence  the  tube  is  very  distensible.     In  performing  ceso- 
phagotomy,  therefore,  care  must  be  taken  not  to  work  round  in 
the  interval  between  the  coats  and  so  open  the  muscular  coat 
on  the  opposite  side  in  mistake  for  the  mucous  coat.    To  prevent 
this  mishap,  an  cesophageal  bougie  may  be  passed  and  cut  down 
upon  at  this  stage  of  the  operation. 

(b)  Excision  of  (Esophageal  Diver ticula. — These  diverticula 
generally  occur  on  the  left  side,  and  they  occupy  the  interval 
between  the  oesophagus  and  the  carotid  sheath,  which  is  thus 
displaced  to  the  lateral  side.     The  entrance  to  the  diverticulum 
lies  opposite  the  sixth  cervical  vertebra,  i.e.  at  the  point  where 


140 


THE  HEAD  AND  NECK 


the  pharynx  and  oesophagus  are  continuous.  After  excision  of 
the  diverticulum,  the  cesophageal  wound  is  closed  horizontally 
to  avoid  the  formation  of  a  stricture. 

In  both  of  these  cesophageal  operations  a  drainage  tube  is 
inserted  to  prevent  any  septic  infection  passing  down  into  the 
thorax  along  the  carotid  sheath. 


Thyreoid  gland  -V— — — 


Longus  colli,  left  border 
Left  recurrent  nerve 


Common  carotid  artery, 
cut 


Thyreoid  cartilage 


Scalenus  anterior 
irenic  nerve 
Middle  cervical  ganglion 

Ascending  cervical  artery,  cut 
Upper  trunk  of  brachial  plexus 
Sympathetic  trunk 

irtebral  vessels 
:alenus  medius 
Inferior  thyreoid  artery 
Mid.  trunk  of  brachial  plexus 
Transverse  cervical  a. 

-  Transverse  scap.  a. 
Lower  trunk  of 
brachial  plexus 

..Subclavian 
artery 


Vagus  nerve 
Left  innominate  vein 

Inferior  cervical  ganglion 


Subclavian  vein 
Thoracic  duct 


Internal  jugular  vein,  cut 


FIG.  44.  — The  Deep  Triangle  of  the  Neck. 

(c)  Ligature  of  the  Vertebral  Artery. — In  this  operation  the 
deep  triangle  of  the  neck  is  more  fully  exposed.  The  vertebral 
artery  arises  from  the  first  part  of  the  subclavian  and  runs 
upwards  and  backwards  behind  the  carotid  sheath.  It  dis- 
appears from  view  at  the  apex  of  the  triangle  by  entering  the 
foramen  in  the  transverse  process  of  the  sixth  cervical  vertebra. 
Shortly  before  it  disappears  it  is  crossed  anteriorly  by  the 
inferior  thyreoid  artery  and,  on  the  left  side,  at  a  lower  level  by 
the  thoracic  duct  (Fig.  44).  From  both  of  these  structures  it 


THE  NECK  141 

is  usually  separated  by  its  companion  vein,  which  runs  down- 
wards in  front  of  it  and  crosses  the  subclavian  artery  to  terminate 
in  the  innominate  vein.  In  order  to  avoid  the  inferior  thyreoid 
artery  and  the  thoracic  duct,  the  surgeon  applies  the  ligature  as 
close  as  possible  to  the  transverse  process  of  the  sixth  cervical 
vertebra,  which  forms  the  most  important  guide  to  the  vertebral 
artery.  It  may  be  necessary  to  tie  the  vertebral  vein  before 
the  artery  is  ligatured,  and  it  may  be  impossible  to  avoid  in- 
cluding some  fibres  of  the  cervical  sympathetic,  which  emerges 
from  the  posterior  wall  of  the  carotid  sheath  in  the  lower  part  of 
the  neck. 

(d)  In  removal  of  the  lower  anterior  group  of  the  deep  cervical 
lymph  glands  good  access  is  essential,  and  it  is  obtained  by  the 
oblique  (p.  135)  or  curvi-linear  (p.  126)  incision  already  described. 

The  external  jugular  vein  is  exposed  and  a  portion  of  it  is 
resected  between  ligatures.  The  fascial  sheath  of  the  sterno- 
mastoid  is  opened,  and  the  muscle  is  divided  about  an  inch  or 
more  above  the  clavicle,  and  the  two  cut  ends  are  widely 
retracted.  This  procedure  exposes  the  carotid  sheath  medially 
and,  to  its  lateral  side,  the  scalenus  anterior,  with  the  phrenic 
nerve  and  the  posterior  belly  of  the  omo-hyoid  on  its  surface. 
The  ascending  cervical  artery,  which  supplies  many  of  the  glands 
of  this  group,  lies  close  to  the  medial  side  of  the  phrenic  nerve. 
In  order  to  avoid  injuring  the  phrenic  nerve  and,  on  the  left  side, 
the  thoracic  duct,  the  glands  are  best  removed  by  the  finger 
covered  with  gauze,  but  if  the  knife  is  used  great  care  must  be 
exercised.  In  an  old -standing  case,  where  the  glands  have 
become  caseous,  the  scalenus  anterior — and  even  the  sterno- 
mastoid — may  be  partially  destroyed,  and  the  phrenic  nerve  is 
then  more  liable  to  injury. 

If  the  lower  anterior  group  is  the  only  group  affected  in  the 
neck,  the  enlargement  is  probably  due  to  an  ascending  infection 
from  the  bronchial  lymph  glands.  As  the  disease  spreads 
upwards  along  the  blood-vessels,  the  lymph  glands  which  lie 
along  the  lower  part  of  the  carotid  sheath  are  the  first  to  be 
involved.  Consequently  these  glands  show  a  more  advanced 
stage  of  the  disease  than  the  glands  lying  along  the  lateral 
border  of  the  scalenus  anterior,  which  will  not  present  the  same 
number  of  caseous  foci.  On  the  other  hand,  in  descending 
infections,  the  higher  glands  of  the  group  are  the  first  to  be 
involved,  and  the  lower  glands  always  show  a  less  advanced 
stage  of  the  disease. 


142  THE  HEAD  AND  NECK 

The  Thoracic  Duct  is  closely  applied  to  the  left  side  of  the 
oesophagus,  as  it  leaves  the  thorax.  It  ascends  into  the  neck 
for  an  inch  or  sometimes  an  inch  and  a  half  above  the  clavicle, 
and  then  turns  laterally  behind  the  carotid  sheath  and  its 
contents,  but  in  front  of  the  vertebral  and  the  inferior  thyreoid 
arteries.  It  usually  crosses  in  front  of  the  vertebral  vein,  but 
in  many  cases  it  passes  behind  that  vessel.  On  reaching  the 
medial  border  of  the  scalenus  anterior,  the  thoracic  duct  passes 
downwards  to  enter  the  postero-lateral  aspect  of  the  union  of 
the  subclavian  and  internal  jugular  veins  of  the  left  side.  Some- 
times it  extends  farther  laterally  on  to  the  surface  of  the  scalenus 
anterior,  and  it  usually  crosses  the  phrenic  nerve.  As  it  lies 
behind  the  carotid  sheath  the  duct  crosses  the  deep  triangle 
(Fig.  44),  where  it  lies  above  the  level  of  the  first  part  of  the  sub- 
clavian artery.  Near  its  termination  the  thoracic  duct  lies  in 
front  of  the  big  vessel.  It  may  terminate  as  a  single  trunk, 
or  it  may  break  up  into  a  number  of  small  branches,  which  join 
the  internal  jugular  and  subclavian  veins  independently  of  one 
another.  If  the  duct  is  injured,  its  ends  must  be  ligatured  if  it 
is  impossible  to  reunite  them. 

The  thoracic  duct  drains  the  lymph  from  both  lower  limbs, 
the  abdominal  walls  and  most  of  the  abdominal  viscera,  and 
the  left  half  of  the  thorax.  In  addition  it  is  joined  near  its 
termination  by  the  subclavian  trunk,  from  the  left  upper 
limb,  and  the  jugular  trunk,  from  the  left  side  of  the  head 
and  neck.  These  two  trunks,  however,  may  end  independently 
in  the  subclavian  and  internal  jugular  veins  respectively. 

The  Subclavian  Artery  arises,  on  the  right  side,  from  the 
innominate  artery  behind  the  sterno-clavicular  joint,  and  it 
arches  upwards  and  laterally,  disappearing  behind  the  scalenus 
anterior.  On  the  left  side,  it  arises  within  the  thorax  from  the 
arch  of  the  aorta,  and  it  lies  behind  the  left  common  carotid 
artery  as  it  enters  the  neck.  The  first  part  of  the  artery  rests  on 
the  cervical  pleura,  and  extends  as  far  as  the  medial  border 
of  the  scalenus  anterior.  It  forms  the  oblique  lower  border  of 
the  deep  triangle  of  the  neck,  and  is  covered  in  front  by  the 
internal  jugular  vein  and  the  vagus  nerve.  On  the  right  side 
the  recurrent  nerve  arises  from  the  vagus  as  it  crosses  the  vessel, 
and  it  runs  upwards  and  medially  deep  to  the  subclavian  and 
common  carotid  arteries.  A  detailed  description  of  the  relations 
of  this  part  of  the  subclavian  artery  is  unnecessary,  as  it  is 
rarely  ligated  by  the  surgeon. 


THE  NECK  143 

The  Thyreo-Cervical  Trunk  (Thyroid  Axis)  arises  from  the 
subclavian  at  the  medial  border  of  the  scalenus  anterior,  and  at 
once  divides  into  the  transverse  scapular  (suprascapular)  (p. 
126);  the  transverse  cervical  (p.  126);  and  the  inferior  thyreoid 
arteries. 

The  Inferior  Thyreoid  Artery  runs  upwards  along  the  medial 
border  of  the  scalenus  anterior  a.nd  behind  the  carotid  sheath 
(internal  jugular  vein).  On  the  left  side,,  the  artery  is  crossed  by 
the  thoracic  duct  close  to  its  origin.  A  little  below  the  sixth 
cervical  vertebra  it  turns  medially  behind  the  sheath  and,  at  the 
point  where  it  makes  the  bend,  it  gives  off  the  ascending  cervical 
artery  (Fig.  44).  It  crosses  in  front  of  the  vertebral  vein  and 
artery,  and  at  the  lateral  border  of  the  longus  colli  it  turns 
downwards  and  runs  in  the  groove  between  the  trachea  and  the 
oesophagus,  overlapped  by  the  lateral  lobe  of  the  thyreoid 
gland.  The  vessel  may  require  to  be  ligated  in  operations  on 
the  thyreoid  gland,  oesophagus,  and  larynx. 

The  first  part  of  the  subclavian  artery  also  gives  off  the 
vertebral  (p.  140)  and  the  internal  mammary  arteries  (p.  503). 

The  Submaxillary  Region  of  the  neck  extends  upwards, 
under  cover  of  the  mandible,  to  the  mylo-hyoid  line  and  down- 
wards to  the  hyoid  bone.  Its  roof  is  formed  by  the  deep  surface 
of  the  mandible  and  by  the  investing  layer  of  the  deep  cervical 
fascia,  which  is  attached  to  the  lower  border  of  the  mandible 
above  and  to  the  hyoid  bone  below.  In  front  and  behind  it  is 
bounded  by  the  bellies  of  the  digastric,  and  the  fascial  roof 
blends  with  the  fascial  sheath  of  the  muscle,  so  that  a  collection 
of  pus  in  this  neighbourhood  is  definitely  circumscribed.  The 
submaxillary  salivary  gland  and  numerous  lymph  glands,  which 
extend  from  the  anterior  belly  of  the  digastric  in  front  to  the 
mandibular  angle  behind,  occupy  the  area,  and  during  their 
examination  the  head  should  be  flexed  in  order  to  relax  the 
strong  fascial  roof.  The  surgeon  stands  behind  the  patient  and 
inserts  the  tips  of  his  fingers  beneath  the  lower  border  of  the 
mandible.  By  pressing  laterally  against  the  bone,  he  is  enabled 
to  detect  even  a  slight  enlargement  of  the  anterior  group  of 
lymph  glands.  The  more  superficial  glands  of  the  posterior 
group,  which  are  intimately  related  to  the  submaxillary  salivary 
gland,  may  be  identified  near  the  angle  of  the  mandible  if  they 
become  enlarged. 

The  floor  of  the  space  is  formed  by  the  mylo-hyoid  in  front 


144  THE  HEAD  AND  NECK 

and  above,  by  the  hyo-glossus  below  and  behind,,  and  by  the 
middle  and  superior  constrictors  of  the  pharynx,  which  appear 
in  the  small  interval  between  the  posterior  belly  of  the  digastric 
and  the  posterior  border  of  the  hyo-glossus.  These  muscles  are 
useful  surgical  landmarks,  as  they  can  be  readily  recognised 
by  the  direction  of  their  fibres. 

The  mylo-hyoid  muscle  arises  from  the  mylo-hyoid  line  on  the  deep  surface 
of  the  mandible,  and  its  fibres  run  downwards  and  medially.  The  posterior 
fibres  reach  the  hyoid  bone,  but  the  anterior  fibres  are  inserted  into  a  fibrous 
raphe,  which  extends  from  the  chin  to  the  hyoid  bone  in  the  median  plane. 
The  nerve  to  the  mylo-hyoid,  which  is  a  branch  from  the  inferior  alveolar 
(inferior  dental)  (p.  183),  lies  on  the  superficial  aspect  of  the  muscle  close 
to  its  origin.  The  mylo-hyoid  may  act  as  an  elevator  of  the  hyoid  bone, 
or,  when  that  bone  is  fixed,  as  a  depressor  of  the  mandible. 

The  posterior  belly  of  the  digastric  arises  from  the  temporal  bone  under 
cover  of  the  mastoid  process.  It  runs  downwards,  medially,  and  forwards 
towards  the  greater  cornu  of  the  hyoid  bone.  It  crosses  the  internal  jugular 
vein,  the  internal  and  external  carotid  arteries,  the  tenth,  eleventh,  and 
twelfth  cerebral  nerves,  etc.,  and  it  is  therefore  a  most  important  landmark 
for  the  surgeon.  It  ends  in  the  intermediate  tendon,  which  is  bound  down 
to  the  greater  cornu  of  the  hyoid  bone  by  a  slip  of  deep  fascia.  The  posterior 
belly  of  the  digastric  is  supplied  by  the  facial  nerve,  which  emerges  from  the 
stylo-mastoid  foramen  close  to  the  origin  of  the  muscle. 

The  anterior  belly  of  the  digastric  passes  upwards,  forwards,  and  medially 
from  the  intermediate  tendon,  and  is  attached  to  the  digastric  fossa  of  the 
mandible.  It  is  placed  on  the  superficial  aspect  of  the  mylo-hyoid  muscle, 
and  is  supplied  by  the  mylo-hyoid  nerve. 

The  digastric  muscle  may  act  as  an  elevator  of  the  hyoid  bone,  or,  if  that 
bone  is  fixed,  as  a  depressor  of  the  mandible. 

The  hyo-glossus,  which  lies  partly  under  cover  of  the  mylo-hyoid,  arises 
from  the  hyoid  bone,  and  its  fibres  run  vertically  upwards,  medial  to  the 
mandible,  forming  the  lateral  surface  of  the  tongue.  The  origin  of  the  hyo- 
glossus  extends  farther  back  on  the  hyoid  bone  than  the  insertion  of  the 
mylo-hyoid,  and,  in  consequence,  its  posterior  part  can  be  seen  in  the  angular 
interval  between  the  greater  cornu  of  the  hyoid  bone  and  the  oblique  posterior 
border  of  the  mylo-hyoid  muscle.  It  is  supplied  by  the  hypoglossal  nerve. 

The  constrictor  muscles  (p.  190)  have  their  fibres  directed  almost  hori- 
zontally as  they  lie  in  this  region. 

The  Submaxillary  Salivary  Gland  is  situated  immediately 
under  the  deep  fascia  and  occupies  nearly  the  whole  space.  It 
lies  on  the  mylo-hyoid  in  front,  but  posteriorly  it  rests  on  the 
hyo-glossus,  and  part  of  it  passes  forwards  deep  to  the  oblique 
posterior  border  of  the  mylo-hyoid.  It  is  a  soft,  lobulated  struc- 
ture of  a  pinkish  colour,  and  its  lobules  may  be  mistaken  for 
lymph  glands,  some  of  which  lie  on  its  superficial  aspect.  The 
submaxillary  duct  (of  Whartori)  emerges  from  the  deep  part  of 
the  gland  and  runs  forwards,  on  the  upper  part  of  the  hyo- 
glossus  and  under  cover  of  the  mylo-hyoid,  to  open  into  the 
floor  of  the  mouth  on  a  small  papilla  at  the  side  of  the  frenulum 


THE  NECK  145 

linguae.  Between  the  same  muscular  layers  lie  the  lingual 
nerve  above,  and  the  hypoglossal  nerve  and  its  accompanying 
(ranine)  vein  below.  Both  nerves  at  first  run  horizontally 
forwards. 

The  Lingual  Artery  lies  on  a  deeper  plane  in  this  part  of 
its  course.  On  entering  the  submaxillary  region  the  vessel  is 
placed  deep  to  the  stylo-hyoid  and  the  posterior  belly  of  the 
digastric,  and  it  passes  under  cover  of  the  posterior  border  of  the 
hyo-glossus.  It  then  runs  forwards  horizontally  just  above 
the  hyoid  bone,  giving  off  its  dorsales  lingua  branches,  which 
reach  the  tongue  by  passing  upwards  and  sinking  into  the  genio- 
glossus  muscle.  A  curved  incision  is  employed  to  expose  the 
artery.  It  begins  just  below  the  chin,  has  its  mid-point  at  the 
greater  cornu  of  the  hyoid  bone,  and  extends  to  near  the  angle 
of  the  mandible.  It  is  carried  down  through  the  deep  fascia, 
and  the  submaxillary  gland  is  then  retracted  upwards  with  the 
flap.  The  various  muscles  are  identified  by  the  direction  of 
their  fibres  (vide  supra),  and  the  hypoglossal  nerve  is  exposed 
lying  on  the  hyo-glossus  in  the  angular  interval  between  the 
two  bellies  of  the  digastric.  In  the  cadaver  the  fascial  slip 
which  binds  the  intermediate  tendon  of  the  digastric  to  the  hyoid 
becomes  stretched  if  the  head  has  been  extended  for  any  length 
of  time,  and  the  tendon  is  carried  upwards,  covering  the  hypo- 
glossal  nerve.  The  hyo-glossus  is  cut  through  parallel  to  and 
below  the  nerve  (a  quarter  of  an  inch  above  the  hyoid  in  the 
cadaver).  In  life  its  fibres  retract  upwards  and  downwards 
and  leave  the  lingual  artery  exposed,  lying  on  the  genio- 
glossus. 

Acute  inflammatory  conditions  in  the  submaxillary  region 
usually  arise  in  connection  with  the  teeth.  The  pus  from  an 
alveolar  abscess  may  make  its  way  through  the  periosteum, 
either  above  or  below  the  attachment  of  the  deep  fascia  to  the 
mandible  (Fig.  45).  In  the  former  case  it  comes  to  the  surface 
after  perforating  the  platysma,  but  in  the  latter  case  it  enters 
the  submaxillary  region  and  gives  rise  to  a  cellulitic  condition 
under  the  deep  fascia.  Although  at  first  strictly  circumscribed, 
if  not  released  the  pus  may  follow  the  course  of  the  lingual 
artery  or  hypoglossal  nerve,  and,  coming  into  contact  with  the 
carotid  sheath,  it  may  give  rise  to  a  spreading  cellulitis  of  the 
neck  (Ludwig's  angina).  These  abscesses  should  be  opened 
by  Hilton's  method  in  order  to  avoid  injuring  the  important 
structures  in  this  neighbourhood. 

10 


146 


THE  HEAD  AND  NECK 


The  Submaxillary  Lymph  Glands  may  be  divided  into  two 
groups : 

(a)  The  anterior  group  lies  in  the  anterior  part  of  the  space, 
between  the  mylo-hyoid  and  the  deep  surface  of  the  mandible. 
They  receive  afferents  from  the  anterior  part  of  the  tongue  and 


Maxilla.. 
Tooth  abscess  - 
Muco-periosteum  of  palate  - 

Tongue  


Periosteum 


Tooth  abscess 


Maxillary  sinus 
Inferior  meatus 

Alveolar  abscess 
Maxilla 


Mucous  mem- 
brane of  cheek 


j-Submaxillary  duct 

Lingual  nerve 
Genio-glossus 
Sublingual  gland 

Genio-hyoid 


Skin  ' 


Digastric,  ant.  belly 

Lymph  gland        / 


Deep  cervical  fascia 


cAbcess 


v  Mylo-hyoid 

Hyoid  bone 


FIG.  45. — Frontal  Section  through  the  Mouth.  Four  varieties  of  alveolar 
abscess  are  shown.  In  the  maxilla,  on  the  right  side,  the  pus  has  spread 
laterally,  forming  an  abscess  under  the  mucous  membrane  ;  on  the  left 
side,  it  has  spread  medially,  forming  a  palatal  abscess.  In  the  mandible, 
on  the  right  side,  the  pus  has  perforated  the  bone  medial  to  the  attach- 
ment of  the  deep  cervical  fascia,  forming  an  abscess  which  is  covered  by 
the  fascia  and  the  skin  ;  on  the  left  side,  the  pus  has  perforated  the  bone 
outside  the  deep  fascia,  forming  an  abscess  immediately  under  the  skin. 

floor  of  the  mouth,  from  the  lower  lip  and  teeth  of  the  lower 
jaw,  and  from  the  submental  lymph  glands. 

(b)  The  posterior  group  lies  in  relation  to  the  deep  and  super- 
ficial aspects  of  the  submaxillary  salivary  gland.  The  superficial 
glands  receive  afferents  from  the  lips,  gums,  and  teeth,  ard 
from  the  anterior  group.  When  enlarged  they  are  usually 
tuberculous,  and  the  infection  can  be  traced  to  the  teeth.  The 
deep  glands  drain  the  lateral  part  of  the  tongue  and  floor  of  the 


THE  NECK  147 

mouth.  They  may  become  infected  secondarily  from  chronic 
tuberculous  disease  of  the  superficial  glands,  but  they  are 
primarily  and  constantly  involved  in  malignant  i  disease  of 
the  areas  which  they  drain.  The  efferents  from  both  groups 
terminate  in  the  upper  anterior  group  of  the  deep  cervical 
glands  (p.  132). 

Good  exposure  of  the  region  is  obtained  by  a  large  curved 
incision  similar  to  that  already  described  for  ligature  of  the 
second  part  of  the  lingual  artery  (p.  145).  This  incision  is  useful 
when  a  cold  abscess  points  beneath  the  skin,  because  the  vitality 
of  the  skin  immediately  over  the  abscess  is  not  interfered  with 
when  the  flap  is  turned  up.  If  a  sinus  is  present,  the  incision 
may  be  made  straighter  so  as  to  excise  it  entirely.  The  skin 
and  platysma  are  undercut  to  afford  good  exposure  and  to  permit 
the  edges  to  be  brought  together  subsequently.  As  soon  as 
the  deep  fascia  is  cut  through,  the  anterior  facial  vein  is  exposed, 
running  downwards  and  backwards  on  the  surface  of  the  sub- 
maxillary  salivary  gland,  but  it  may  be  displaced  or  it  may  be 
embedded  amongst  the  enlarged  lymph  glands.  It  enters  the 
region  by  piercing  the  deep  fascia  at  the  anterior  border  of  the 
masseter  muscle,  just  behind  the  external  maxillary  (facial) 
artery,  and  leaves  it,  as  the  common  facial  vein,  by  passing 
superficial  to  the  posterior  belly  of  the  digastric.  If  it  is  cut, 
both  ends  must  be  ligatured,  as  they  may  give  rise  to  severe 
haemorrhage,  especially  when  the  vessel  is  injured  near  its 
junction  with  the  internal  jugular  vein  (p.  118).  After  the  an- 
terior facial  vein  has  been  dealt  with,  the  superficial  lymph 
glands  may  be  removed,  but  they  must  be  distinguished  from 
the  lobules  of  the  salivary  gland,  which  closely  resemble  them 
in  appearance. 

The  removal  of  the  deep  lymph  glands  is  complicated  by  their 
relation  to  the  external  maxillary  (facial)  artery.  Normally, 
the  vessel  runs  first  upwards  and  then  forwards  and  downwards 
in  a  well-marked  groove  on  the  deep  surface  of  the  salivary 
gland,  but  it  may  be  displaced  or  surrounded  by  the  lymph  glands 
when  they  are  enlarged.  The  salivary  gland  is  turned  upwards 
and  the  position  of  the  artery  is  ascertained,  but  the  vessel  is 
liable  to  be  wounded  as  it  crosses  the  inferior  border  of  the 
mandible  (p.  174).  Thereafter  the  enlarged  lymph  glands  can 
be  safely  taken  away.  If  the  glands  are  malignant,  the  whole 
group  (i.e.  both  superficial  and  deep),  together  with  the  salivary 
gland  and  the  portion  of  the  external  maxillary  (facial)  artery 

10  a 


148  THE  HEAD  AND  NECK 

in  relation  to  it,  will  require  excision,  possibly  with  many 
neighbouring  structures. 

Portions  of  the  submaxillary  salivary  gland  may  be  removed 
without  the  occurrence  of  a  salivary  fistula,  which  only  follows 
injury  to  the  duct  itself  or  to  its  larger  tributaries. 

The  Genio-hyoid  is  a  narrow,  strap-like  muscle,  which  arises  from  the 
lower  part  of  the  mental  spine  (genial  tubercle),  and  is  inserted  into  the  hyoid 
bone.  It  lies  immediately  under  cover  of  the  mylo-hyoid,  and  is  supplied  by 
the  hypoglossal  nerve.  It  acts  as  an  elevator  of  the  hyoid  bone  or  as  a  de- 
pressor of  the  mandible. 

The  Genio-glossus  muscle  arises  just  above  the  genio-hyoid,  and  it  widens 
out  in  a  fan-shaped  manner  as  its  fibres  pass  backwards.  The  lowermost 
fibres  run  downwards  and  backwards  to  the  hyoid  bone.  In  front  they  are 
covered  by  the  genio-hyoid,  and  behind  they  disappear  under  cover  of  the 
hyo-glossus,  but  between  these  two  muscles  they  lie  in  contact  with  the 
mylo-hyoid.  The  uppermost  fibres  pass  into  the  tongue,  under  cover  of  the 
hyo-glossus.  The  genio-glossus  receives  its  nerve-supply  from  the  hypo- 
glossal.  The  lower  and  middle  fibres  protrude  the  tongue  (Fig.  50),  while 
the  upper  fibres  retract  it.  When  the  muscle  acts  as  a  whole  it  depresses 
the  tongue. 

The  Stylo-glossus  runs  downwards  and  forwards  from  the  styloid  process 
to  the  side  of  the  tongue,  and  in  most  of  its  extent  it  is  covered  by  the 
mandible.  It  helps  the  anterior  fibres  of  the  genio-glossus  to  retract  the 
tongue,  and  is  supplied  by  the  hypoglossal  nerve. 

The  Sublingual  Salivary  Gland  lies  immediately  below  the 
mucous  membrane  of  the  anterior  part  of  the  floor  of  the  mouth, 
and  it  forms  a  small  swelling,  which  can  be  readily  appreciated 
by  the  tip  of  the  tongue.  It  lies  on  the  surface  of  the  anterior 
part  of  the  genio-glossus,  and  is  placed  under  cover  of  the  man- 
dible. It  possesses  numerous  ducts,  which  open  directly  into 
the  floor  of  the  mouth.  Occlusion  of  these  ducts  gives  rise  to  a 
cystic  swelling  (ranula),  which  is  sometimes  bilateral  in  the 
floor  of  the  mouth  and  lies  under  the  tongue. 

The  Lingual  Nerve  (p.  183)  runs  forwards  on  the  upper  part 
of  the  hyo-glossus  above  the  submaxillary  duct,  which  passes 
upwards  under  cover  of  it  anteriorly.  It  disappears  under 
cover  of  the  sublingual  gland,  and  sinks  into  the  genio-glossus 
to  reach  the  mucous  membrane  of  the  tongue.  It  supplies  the 
anterior  two-thirds  of  the  tongue  with  ordinary  sensation  and 
with  the  special  sense  of  taste,  the  latter  through  the  fibres  of 
the  chorda  tympani,  which  joins  the  lingual  nerve  in  the  infra- 
temporal  fossa  (pterygo-maxillary  region). 

Development  of  the  Neck. — In  the  early  weeks  of  fcetal  life, 
certain  transverse  ridges,  which  are  known  as  the  visceral  or 
branchial  arches,  appear  on  each  side  of  the  neck,  and  their 
inner  surfaces  project  into  that  part  of  the  foregut  (p.  287) 


THE  NECK  149 

which  gives  rise  to  the  mouth  and  pharynx.  There  are  six  of 
these  arches,  but  the  lower  two  do  not  cause  any  elevation  on  the 
ectodermal  surface.  The  arches  are  separated  from  one  another 
on  the  outside  by  grooves  which  are  termed  the  visceral  clefts, 
and  on  the  inside  by  grooves  which  are  termed  the  visceral 
pouches.  The  grooves,  which  never  break  down  in  the  human 
embryo,  consist  of  an  outer  layer  of  ectoderm  and  an  inner  layer 
of  entoderm,  the  two  together  forming  the  cleft  membrane. 
Each  arch  contains  a  bar  of  cartilage,  a  muscle  mass,  a  nerve, 
and  an  artery. 

At  the  period  when  the  branchial  arches  develop,  the  embryo 
possesses  two  ventral  aortse,  which  arise  from  the  truncus 
arteriosus,  and  two  dorsal  aortas.  Each  ventral  aorta  is  con- 
nected with  the  dorsal  aorta  of  the  same  side  by  six  aortic  arches, 
each  of  which  supplies  one  branchial  arch  and  the  cleft  caudal 
to  it.  The  external  carotid  is  derived  from  the  distal  portion 
of  the  ventral  aorta,  while  the  internal  carotid  represents 
the  third  aortic  arch  and  the  distal  part  of  the  dorsal  aorta. 
From  this  it  is  clear  that  branchial  fistulse,  which  develop  in 
connection  with  the  first  or  second  clefts,  must  pass  deep  to 
the  external  carotid  but  superficial  to  the  internal  carotid 
artery. 

The  cartilage  of  the  first  arch  is  known  as  Meckel's  cartilage. 
It  is  almost  entirely  replaced  by  the  mandible,  but  its  cephalic 
extremity  forms  the  greater  part  of  the  malleus.  The  cartilage 
of  the  second  arch  forms  the  tip  of  the  styloid  process,  the  stylo- 
hyoid  ligament,  the  lesser  cornu,  and  a  part  of  the  body  of  the 
hyoid  bone.  The  cartilage  of  the  third  arch  forms  the  greater 
cornu  and  the  remainder  of  the  body  of  the  hyoid  bone,  while 
the  cartilages  of  the  lower  arches  take  part  in  the  formation  of 
the  framework  of  the  larynx. 

The  muscle  mass  of  the  first  arch  develops  into  the  muscles  of 
mastication,  which  are  supplied  by  the  nerve  of  the  first  arch, 
the  mandibular  division  of  the  trigeminal.  The  platysma  and 
the  muscles  of  facial  expression  are  derived  from  the  muscle  mass 
of  the  second  arch,  and  are  innervated  by  the  facial  nerve,  which 
is  the  nerve  of  the  second  arch.  The  muscle  mass  of  the  third 
arch  forms  the  stylo-pharyngeus ,  and  its  nerve-supply  is  obtained 
from  the  glosso-pharyngeal,  which  is  the  nerve  of  the  third  arch. 
It  is  probable  that  the  constrictor  muscles  of  the  pharynx  have 
a  similar  origin.  Lower  down  in  the  series  our  knowledge  of 
the  history  of  the  muscle  mass  is  less  definite.  The  crico-thyreoid 


THE  HEAD  AND  NECK 


muscle  is  derived  from  the  fourth  arch,  and  is  supplied  by  the 
external  branch  of  the  superior  laryngeal,  which  is  the  nerve  of 
that  arch.  The  muscle  masses  of  the  fifth  and  sixth  arches  form 
the  intrinsic  muscles  of  the  larynx,  which  are  supplied  by  the 
recurrent  (laryngeal)  nerve — the  nerve  of  these  arches.  Of  the 
visceral  clefts  all  but  the  first,  which  forms  the  external  acoustic 
meatus,  disappear  entirely.  The  first  visceral  pouch  forms  the 
tympanum  and  the  auditory  (Eustachian)  tube,,  so  that  the 
tympanic  membrane  occupies  the  site  of  the  cleft  membrane. 
Remains  of  the  second  pouch  form  the  supra-tonsillar  fossa 
(p.  1 88)  and  the  pharyngeal  recess  (of  Rosenmiiller)  (p.  190). 


1st  Branchial 
cleft 

2nd  Branchial 
pouch • 

2nd  Branchial . 
cleft 


3rd  Branchial 
jx>uch  • 


4th  Bran 

pouch 

4th  Branchial  .."T 
cleft 


Separating  membrane    /  / 
1st  cleft  =  tympanum i'/ 
and  tube  '  '        / 


5th  Branchial  pouch 


FIG.  46. — Scheme  showing  the  Branchial  Pouches,  Clefts  and  Arches 
and  some  of  their  derivatives. 

The  upper  two  branchial  arches  develop  much  more  rapidly 
than  the  lower  arches,  which  are  soon  overlapped  and  hidden 
by  the  second.  The  ectodermal  covering  of  the  second  arch 
comes  into  contact  and  fuses  with  the  ectoderm  caudal  to  the 
fourth  cleft.  In  this  way  the  second,  third,  and  fourth  clefts 
no  longer  open  on  the  surface,  but  instead  they  open  into  a 
common  space  termed  the  cervical  sinus.  This  enclosed  ecto- 
derm normally  disappears,  but  the  persistence  of  any  part  of  it 
may  lead  to  the  formation  of  branchial  cysts  or  fistulse. 

A  Blind  External  Branchial  Fistula  is  the  most  frequent 
deformity  arising  from  persistence  of  the  ectoderm  which  lines 
the  cervical  sinus  and  normally  disappears.  It  is  met  with 
usually  near  the  anterior  border  of  the  sterno-mastoid,  but  the 


THE  NECK  151 

site  of  the  opening  in  no  way  locates  the  individual  cleft  which 
is  at  fault.  Just  as  the  upper  arches  and  clefts  leave  more  normal 
remains  than  the  lower,  so  it  is  found  clinically  that  abnormal 
remains  usually  belong  to  the  upper  members  of  the  series. 

In  the  human  embryo  the  cleft  membrane  never  breaks  down 
as  it  does  in  fishes,  and  it  is  probable  that,  in  cases  where  a  bran- 
chial fistula  is  stated  to  have  been  complete,  the  thin  cleft 
membrane  has  been  destroyed  by  the  probe  or  length  of  fishing- 
gut  or  catgut  which  has  been  introduced  into  the  fistula  to 
examine  its  track. 

This  condition  can  be  satisfactorily  treated  only  by  dis- 
secting out  the  whole  track,  for,  unless  this  is  done,  recurrence  is 
certain.  An  incision  is  made  around  the  fistulous  opening,  and 
it  is  carried  upwards  along  the  anterior  border  of  the  sterno- 
mastoid  as  far  as  is  necessary.  A  fine  probe,  introduced  into  the 
fistula  as  it  is  being  dissected,  is  found  to  sink  gradually  through 
the  superficial  fascia  and  the  platysma,  and  to  pierce  the  deep 
fascia  about  the  level  of  the  upper  border  of  the  thyreoid 
cartilage. 

In  the  majority  of  cases  the  fistula  is  derived  from  the  second 
visceral  cleft.  Consequently,  as  it  is  traced  upwards,  it  will  be 
found  to  lie  superficial  to  the  structures  derived  from  the  third 
and  lower  arches,  e.g.  the  internal  carotid  artery  and  the  glosso- 
pharyngeal  nerve,  but  deep  to  those  developed  in  relation  to 
the  upper  two  arches.  It  is  therefore  crossed  by  the  lingual, 
occipital,  posterior  auricular,  and  external  carotid  arteries, 
and  by  the  stylo-hyoid  ligament  and  the  hypoglossal  nerve. 
If  the  fistula  extends  upwards  to  the  region  of  the  supra-tonsillar 
fossa  or  the  pharyngeal  recess  (of  Rosenmuller)  (p.  190),  it  will 
pass  between  the  stylo-hyoid  and  stylo -pharyngeus  muscles, 
and  it  has  already  been  explained  (p.  149)  why  the  fistula  must 
pass  between  the  two  carotid  arteries.  In  order  to  remove  the 
upper  part  of  the  fistula  entirely,  the  probe  is  pushed  through 
the  cleft  membrane  into  the  supra-tonsillar  fossa  or  pharyngeal 
recess,  as  the  case  may  be.  The  fistula  is  then  divided,  and, 
after  the  lower  part  has  been  removed,  the  upper  part  is  attached 
to  the  probe  and  turned  inside  out  by  pulling  the  probe  out 
through  the  mouth.  In  this  way  the  whole  of  the  fistula  can 
be  completely  excised. 

Branchial  cysts  may  be  mistaken  for  enlarged  lymph  glands, 
but  they  only  occur  singly  and  are  unilateral.  They  contain 
a  glairy  fluid  under  normal  conditions,  but  if  they  are  infected 


152  THE  HEAD  AND  NECK 

there  may  be  some  difficulty  in  making  a  correct  diagnosis  until 
the  cyst  wall  is  exposed.  Unlike  other  simple  cysts,  they  are 
situated  under  the  deep  fascia,  and  closely  resemble  a  glandular 
abscess. 

The  Anterior  Median  Line  of  the  Neck.— This  area 

may  be  subdivided  into  (i)  a  supra-hyoid  or  lingual  region,  (2)  a 
laryngeal  region,  which  extends  from  the  hyoid  bone  to  the 
cricoid  cartilage,  and  (3)  a  tracheal  region,  lying  below  the 
cricoid  cartilage. 

The  Supra-hyoid  Region  is  triangular  in  shape.  It  is  bounded 
laterally  by  the  anterior  bellies  of  the  two  digastric  muscles 
and  below  by  the  hyoid  bone.  The  roof  is  formed  by  the  in- 
vesting layer  of  the  deep  cervical  fascia,  which  is  attached  to 
the  mandible  above  and  to  the  hyoid  bone  below,  and  blends 
with  the  fascial  sheaths  of  the  digastric  on  each  side.  The 
floor  of  the  region  is  formed  by  the  two  mylo-hyoid  muscles, 
which  meet  at  the  median  raphe  (p.  144). 

The  submental  or  supra-hyoid  lymph  glands  are  two  small 
pea-like  bodies  which  lie  just  above  the  hyoid  bone,  and  they 
can  often  be  felt  in  the  living  subject.  They  receive  afferents 
from  the  chin,  the  central  portions  of  the  lower  lip,  the  lower 
incisor  teeth  and  gums,  the  floor  of  the  mouth,  and  the  tip  of  the 
tongue.  Abscess  or  lymph-adenitis  in  connection  with  the  sub- 
mental  lymph  glands  causes  a  swelling  which  projects  downwards 
below  the  chin,  as  it  is  prevented  from  rising  up  into  the  mouth 
by  the  mylo-hyoid  muscles.  Lingual  dermoids,  on  the  other 
hand,  or  cysts  and  solid  tumours  in  connection  with 
remains  of  the  thyreo-glossal  duct  (p.  169),  bulge  upwards  into 
the  floor  of  the  mouth,  since  they  lie  on  the  deep  surface  of  the 
mylo-hyoid  muscles.  The  efferents  from  the  submental  lymph 
glands  pass  laterally  on  the  surface  of  the  mylo-hyoids  and 
open  into  the  submaxillary  lymph  glands. 

Good  access  to  the  glands  is  obtained  by  a  horizontal  incision 
just  above  the  hyoid  bone.  It  should  pass  through  the  deep 
fascia,  which  is  undercut  so  as  to  expose  the  anterior  bellies  of 
the  digastric,  and  these  muscles  act  as  a  guide  to  the  level 
of  the  slightly  deeper  floor.  The  glands  can  then  be  removed 
from  the  floor  of  the  triangle  without  trouble. 

In  the  removal  of  a  lingual  dermoid  a  vertical  supra- 
hyoid  incision  is  carried  through  the  deep  fascia  to  the  muscular 
floor  of  the  submental  triangle,  and  both  edges  are  undercut. 
The  median  raphe  is  split  and  the  mylo-hyoid  muscles  are  re- 


THE  NECK 


153 


tracted  from  one  another.  In  the  normal  condition  this  pro- 
cedure would  expose  the  genio-hyoids  lying  side  by  side  at  the 
median  plane,  but  when  a  dermoid  cyst  is  present  it  separates 
the  two  muscles.  At  a  deeper  level  the  cyst  separates  the  two 
genio-glossi,  and  its  upper  surface  may  be  in  contact  with  the 
mucous  membrane  of  the  anterior  part  of  the  floor  of  the  mouth. 
The  cyst  wall  is  separated  from  these  structures  by  blunt  dis- 
section, but  it  may  have  to  be  evacuated  prior  to  removal. 
The  surgical  approach  for  removal  of  advanced  malignant 


Side  of  tongue 
Upper  lip 


Cut  edges  of  mucous  membrane 


Mandible,  cut 


Sublingual  gland 


^\'~   Lingual  nerve 
Submaxillary 
"   duct 


Submaxillary 
,  deep 


Mylo-hyoid 


Hypoglossal  nerve 


Mylo-hyoid 


Genio-hyoid        / 
Genio-glossus 

FIG.  47. — Surgical  approach  for  the  Removal  of  Advanced  Malignant  Disease 
of  the  Tongue.  The  mandible  has  been  divided,  lateral  to  the  mental 
spine,  and  the  mylo-hyoid  has  been  cut.  The  operation  is  described 
below. 

disease  of  the  back  of  the  tongue,  epiglottis,  floor  of  the  mouth, 
and  fauces  may  be  obtained  through  the  supra-hyoid  region.  A 
median  vertical  incision  is  made  through  the  lower  lip  and  skin 
of  the  chin  and  neck  down  to  the  hyoid  bone.  Before  the  man- 
dible is  divided,  holes  are  drilled  through  it  on  each  side  of  the 
symphysis,  so  that  the  two  halves  may  subsequently  be  retained 
in  position  by  wiring.  The  bone  is  then  divided,  and  the  median 
raphe  of  the  mylo-hyoids  is  split.  The  two  halves  of  the  jaw 
can  now  be  separated  widely,  and  the  mucous  membrane  of  the 
floor  of  the  mouth  is  cut  through  with  scissors,  near  its  reflection 


154  THE  HEAD  AND  NECK 

on  to  the  gums,  from  the  median  plane  as  far  back  as  the  glosso- 
palatine  arch  (anterior  pillar  of  the  fauces)  on  the  diseased  side. 

The  cutting  of  the  mucous  membrane  permits  the  tongue  to 
be  dragged  over  towards  the  healthy  side,  and  exposes,  from 
before  backwards,  the  sublingual  gland  lying  on  the  genio-glossus 
and  the  submaxillary  (Wharton's)  duct,  and  the  lingual  nerve 
resting  on  the  upper  part  of  the  hyo-glossus  (Fig.  47).  By  blunt 
dissection  the  wound  is  deepened  between  the  hyo-glossus  and 
stylo -glossus  medially,  and  the  mylo-hyoid  and  stylo -hyoid 
laterally,  until  the  hypoglossal  nerve  is  exposed  and  the  hyoid 
bone  is  reached.  The  hyo-glossus  is  next  cut  away  from  the 
hyoid  bone,  and  it  is  probable  that  the  hypoglossal  nerve,  on 
the  superficial  aspect  of  the  muscle,  and  the  lingual  artery,  on 
its  deep  aspect,  will  be  divided  at  this  stage.  The  submaxillary 
duct,  the  lingual  nerve,  and  the  stylo -glossus  are  next  cut 
through.  If  the  palatine  tonsil  and  adjoining  mucous  membrane 
are  involved,  the  glosso- palatine  arch  (anterior  pillar  of  the 
fauces)  is  divided  and  the  diseased  area  taken  away.  The  actual 
removal  of  the  tongue  is  described  on  p.  187. 

The  Depressor  Muscles  of  the  Hyoid  Bone  form  a  double 
layer  of  muscle,  clothing  the  trachea  and  larynx.  The  super- 
ficial layer  consists  of  the  sterno-hyoid  and  the  anterior  belly 
of  the  omo-hyoid,  which  lies  to  its  lateral  side.  The  deep  layer 
is  formed  by  the  sterno-thyreoid  below  and  by  the  thyreo- 
hyoid  above.  The  former  is  closely  applied  to  the  surface  of 
the  lateral  lobe  of  the  thyreoid  gland,  while  the  latter  is  in 
relation  to  the  thyreo-hyoid  membrane. 

The  Ansa  Hypoglossi  lies  on  the  anterior  surface  of  the 
carotid  sheath  opposite  the  cricoid  cartilage.  It  is  formed  by 
the  union  of  the  ramus  descendens  hypoglossi  (p.  124)  with  & 
descending  branch  from  the  cervical  plexus  (C.  2  and  3),  and  it 
supplies  all  the  depressor  muscles  of  the  hyoid  bone  except  the 
thyreo-hyoid,  which  is  supplied  by  the  hypoglossal  nerve 
(p.  124). 

The  Laryngeal  Region. — The  larynx  is  covered  by  the 
depressor  muscles  of  the  hyoid  bone,  the  lateral  lobes  of 
the  thyreoid  gland,  and  the  crico-thyreoid  muscles.  It  occupies 
a  lower  position  in  the  adult  than  it  does  in  the  child.  In  an 
infant  three  months  old  the  cricoid  cartilage  lies  opposite  the 
fourth  cervical  vertebra. 

The  Thyreoid  cartilage  consists  of  two  expanded  laminae,  which  meet  in 
front  at  an  angle,  the  laryngeal  prominence,  but  are  widely  separated  behind. 


THE  NECK  155 

From  the  upper  and  lower  extremities  of  the  posterior  border  of  each  lamina 
the  superior  and  inferior  cornua  project.  The  latter  articulates  with  the  side 
of  the  cricoid  cartilage  by  means  of  a  diarthrodial  joint. 

The  Cricoid  cartilage  is  narrow  in  front,  but  it  is  much  deeper  posteriorly, 
and  helps  to  fill  in  the  gap  caused  by  the  wide  separation  of  the  laminae 
of  the  thyreoid  cartilage.  This  gap  is  still  further  diminished  by  the  two 
Arytenoid  cartilages,  which  are  situated  on  the  upper  border  of  the  posterior 
part  of  the  cricoid.  These  little  cartilages  are  pyramidal  in  shape,  and  their 
bases  articulate  with  the  cricoid  by  diarthrodial  joints.  The  anterior  basal 
angle  (vocal  process)  projects  forwards  and  gives  attachment  to  the  vocal 
fold  (true  vocal  cord),  while  the  lateral  basal  angle  (muscular  process)  receives 
important  muscular  attachments.  At  its  apex  the  arytenoid  cartilage  is 
capped  by  the  corniculate  cartilage  (of  Santorini). 

The  thyreo-hyoid  membrane  connects  the  upper  border  of  the 
thyreoid  cartilage  to  the  upper  and  posterior  part  of  the  hyoid 
bone.  Its  superficial  surface  is  closely  applied  to  the  thyreo- 
hyoid  muscle,  while  its  deep  surface  is  separated  from  the 
epiglottis  and  the  anterior  wall  of  the  laryngeal  vestibule  by  a 
pad  of  fat.  A  bursa  is  placed  between  the  posterior  surface  of 
the  hyoid  bone  and  the  upper  part  of  the  thyreo-hyoid  membrane 
to  facilitate  the  movements  of  swallowing,  in  which  the  thyreoid 
cartilage  ascends  behind  the  hyoid  bone.  When  it  is  enlarged 
the  bursa  may  be  mistaken  for  a  thyreo-glossal  cyst  (p.  169), 
as  it  lies  in  the  median  plane,  but  the  laryngeal  lymph  glands, 
which  also  lie  on  the  thyreo-hyoid  membrane,  and  the  possible 
presence  of  accessory  thyreoids  must  be  borne  in  mind  when 
making  the  diagnosis. 

The  conus  elasticus  (crico-thyreoid  membrane}  is  attached 
below  to  the  upper  border  of  the  cricoid  cartilage,  and  passes 
upwards  under  cover  of  the  lower  border  of  the  lamina  of  the 
thyreoid  cartilage.  Its  upper  border  is  attached  in  front  to 
the  deep  surface  of  the  thyreoid  angle,  and,  behind,  to  the  vocal 
process  of  the  arytenoid  cartilage.  In  the  rest  of  its  extent  it 
is  free  and  forms  the  vocal  ligament,  which  is  one  of  the  important 
constituents  of  the  vocal  fold  (true  vocal  cord). 

The  epiglottis  is  a  leaf-shaped  cartilage,  which  lies  in  the 
anterior  wall  of  the  laryngeal  vestibule.  Its  wide  upper  end  is 
free  and  projects  above  the  hyoid  bone  in  relation  to  the  dorsum 
of  the  tongue,  while  its  narrow  lower  end  is  attached  to  the 
deep  surface  of  the  thyreoid  angle.  Anteriorly,  the  epiglottis  is 
separated  from  the  thyreo-hyoid  membrane  by  a  pad  of  fat, 
and  is  attached  by  a  ligament  to  the  deep  surface  of  the  hyoid 
bone.  The  mucous  membrane  passes  from  the  dorsum  of  the 
tongue  to  the  front  of  the  upper  part  of  the  epiglottis,  forming 
the  floor  of  a  depression,  which  is  divided  into  two  by  the  glosso- 


156 


THE  HEAD  AND  NECK 


epiglottic  fold.  These  depressions — the  valleculce — are  bounded 
behind  by  transverse  ridges,  which  extend  from  the  side  of  the 
epiglottis  to  the  lateral  walls  of  the  pharynx.  The  floor  of  the 
vallecula  lies  immediately  above  and  behind  the  hyoid  bone 

(Fig.  50)- 

Over  the  free  upper  border  of  the  epiglottis  the  mucous 
membrane  of  the  mouth  becomes  continuous  with  that  of  the 


Tongue 


Hyoid 
Plica  vocalis 

Rima  glottidi 

Recessus  piriformis 

Superior  cornu 
of  thyreoid 


Pharyngeal  wall 
(cut) 


Glosso-epiglottic 
fold 


Vallecula 

Pharyngo- 
epiglottic  fold 

r Epiglottis 

Tubercle  of 
epiglottis 

Ary-epiglottic 

fold 

Laryngeal  ventricle 

Plica  ventricularis 
Cuneiform  cartilage 

Corniculate 
'cartilage 

Mucous  membrane 
covering  posterior 
aspect  of  cricoid 
cartilage 


FIG.  48. — Upper  Aperture  of  the  Larynx,  exposed  by  cutting  through 
the  posterior  wall  of  the  pharynx. 

larynx.  A  fold  of  mucous  membrane  stretches  from  each  side 
of  the  epiglottis  downwards,  backwards,  and  medially  to  the 
apex  of  the  arytenoid  cartilage  (ary-epiglottic  folds).  These 
folds,  together  with  the  epiglottis,  form  the  boundaries  of  the 
upper  opening  into  the  larynx,  and  owing  to  the  obliquity  of  its 
lateral  margins,  the  plane  of  the  opening  looks  almost  directly 
backwards.  Between  the  ary-epiglottic  fold  and  the  pharyngo- 
epiglottic  fold  the  mucous  membrane  lines  a  small  depression — 
the  recessus  piriformis — which  lies  in  close  relation  to  the  deep 
surface  of  the  thyreo-hyoid  membrane.  This  area  is  supplied 


THE  NECK  157 

by  the  internal  laryngeal  nerve,  and  the  lodgment  of  foreign 
bodies  in  it  at  once  sets  up  a  fit  of  uncontrollable  coughing. 
They  may  be  removed  by  the  finger,  which  is  passed  backwards 
into  the  mouth  close  to  the  dorsum  of  the  tongue,  until  the  epi- 
glottis is  felt.  The  recessus  piriformis  can  be  explored  postero- 
lateral  to  the  epiglottis  (Fig.  48). 

The  uppermost  part  of  the  larynx  is  termed  the  vestibule. 
Its  cavity  narrows  from  above  downwards,  and  is  limited  below 
by  two  inwardly  projecting  ridges  on  its  lateral  walls,  the  ven- 
tricular folds  (false  vocal  cords). 

The  laryngeal  ventricle  is  bounded  above  by  the  ventricular 
folds,  and  below  by  the  vocal  folds  (true  vocal  cords),  which  are 
separated  from  one  another  by  the  rima  glottidis,  and  lie  on  a 
level  with  the  fifth  cervical  vertebra.  The  vocal  fold  consists 
of  the  ligamentum  vocale  (p.  155),  to  the  lateral  aspect  of  which 
the  vocalis  muscle  is  closely  applied.  Its  medial  aspect  is  so 
firmly  bound  down  to  the  mucous  membrane  that  it  presents  a 
whitish  colour  on  laryngoscopic  examination.  In  front,  the 
vocal  fold  is  attached  to  the  thyreoid  angle,  and  behind,  to  the 
vocal  process  of  the  arytenoid  cartilage.  The  intimate  relation 
of  the  mucous  membrane  to  the  vocal  fold  is  of  great  importance 
in  connection  with  oedema  glottidis.  Elsewhere  in  the  larynx 
the  submucous  tissue  is  very  lax  and  distensible.  When  oedema 
occurs  in  this  situation  it  cannot  spread  downwards  beyond  the 
vocal  folds.  In  consequence,  the  laryngeal  ventricle  may  be  so 
encroached  on  by  the  swollen  mucous  membrane  as  to  hinder 
the  in-take  of  air  to  a  serious  or  even  fatal  extent. 

The-n'wwz  glottidis  is  the  narrowest  part  of  the  respiratory 
tract,  and  measures  i  inch  antero  -  posteriorly  by  J  inch 
transversely.  It  corresponds  in  level  to  the  lower  part  of  the 
laryngeal  prominence. 

On  laryngoscopic  examination  the  observer  can  see  the  ex- 
panded upper  end  of  the  epiglottis  and  the  ary-epiglottic  folds. 
In  the  posterior  part  of  the  latter  two  elevations  can  be  made 
out ;  the  posterior  is  produced  by  the  corniculate  cartilage  (of 
Santorini)  and  the  anterior  by  the  cuneiform  cartilage  (of  Wris- 
berg),  which  is  a  nodule  of  yellow  elastic  cartilage  embedded  in 
the  fold.  Within  the  boundaries  of  the  aperture  both  the 
ventricular  and  vocal  folds  (false  and  true  vocal  cords)  can  be 
examined  (Fig.  49).  The  former,  which  are  reddish  in  colour, 
are  more  widely  separated,  as  a  rule,  and  have  only  a  small  range 
of  movement ;  the  latter  are  whitish  in  colour  and  move  freely 


158  THE  HEAD  AND  NECK 

during  phonation.  In  quiet  respiration  the  rima  glottidis  is 
triangular  with  the  apex  in  front,  but  in  forced  breathing  it 
becomes  diamond-shaped  owing  to  lateral  rotation  of  the  vocal 
processes  of  the  arytenoids.  During  high  notes  the  vocal  folds 
become  adducted,  and  only  the  posterior  part  of  the  glottis, 
i.e.  the  part  between  the  two  arytenoids,  remains  open.  A 
yellowish  elevation  may  be  observed  in  the  posterior  part  of 
the  vocal  fold.  It  is  due  to  the  vocal  process  of  the  arytenoid. 
In  addition  to  the  boundaries  of  the  aperture  and  the  interior 
of  the  larynx,  a  good  view  may  be  obtained  of  the  recessus 
piriformis  and  the  valleculse,  and  if  the  vocal  folds  are  widely 
abducted,  the  interior  of  the  trachea  may  be  examined.  It 


Base  of  tongue 


Glosso- 

epiglottic 

fold 

Epiglottis 
Tubercle- 
Plica  vocalis 


Cuneiform  cartilage' 

Corniculate  cartilage 

FIG.  49.  — The  Larynx  as  seen  in  the  living  subject  by  means  of  the 
Laryngoscope. 

must  be  remembered  that  irregular  appearances  may  be  caused 
by  the  cicatricial  contraction  which  commonly  follows  ulceration 
in  this  region. 

Polypi  and  other  growths,  which  may  occur  in  relation  to 
the  epiglottis,  ary-epiglottic  folds,  ventricular  and  vocal  folds, 
may  be  removed  via  the  mouth  by  the  intralaryngeal  method. 
If  this  is  not  possible,  satisfactory  access  may  be  obtained  by 
sub-hyoid  pharyngotomy  (p.  159)  or  thyreotomy  (p.  162). 

The  lymph  vessels  of  the  larynx  may  be  subdivided  into  a 
supraglottic  and  an  infraglottic  group.  They  communicate 
freely  with  one  another  in  the  posterior  wall  of  the  larynx,  but 
across  the  vocal  folds  the  connections  are  few  and  irregular. 
The  supraglottic  efferents  follow  the  course  of  the  internal  laryn- 
geal  nerve  (p.  159)  and  open  into  the  upper  anterior  group  of  the 
deep  cervical  lymph  glands.  The  infraglottic  efferents  run 


THE  NECK  159 

downwards  in  the  groove  between  the  trachea  and  the  oeso- 
phagus, close  to  the  recurrent  nerve,  and  open  into  the  lower 
anterior  group  of  the  deep  cervical  lymph  glands.  In  extrinsic 
cancer  of  the  larynx  the  supraglottic  lymphatics  are  involved, 
but  in  the  intrinsic  variety  the  spread  occurs  along  the  infra- 
glottic  vessels. 

The  upper  aperture  of  the  larynx  can  be  brought  to  the 
surface  by  the  operation  of  Sub-hyoid  Pharyngotomy.  A 
transverse  incision  is  made  just  below  the  hyoid  bone.  This 
divides  the  skin,  the  superficial  fascia,  the  platysma,  and  the 
deep  fascia.  The  sterno-hyoid,  the  omo-hyoid,  and  the  thyreo- 
hyoid  are  cut  through,  but  their  upper  ends  are  left  sufficiently 
long  to  allow  them  to  be  sutured  subsequently.  The  thyreo- 
hyoid  membrane,  which  is  now  completely  exposed,  is  incised 
horizontally,  and  in  doing  so  the  surgeon  is  careful  not  to  injure 
the  internal  laryngeal  nerve  and  its  accompanying  artery  (p.  121) 
by  extending  the  incision  beyond  the  lateral  border  of  the 
thyreo-hyoid  muscle. 

The  internal  laryngeal  nerve  is  a  branch  of  the  superior  laryngeal  nerve, 
which  arises  from  the  vagus  a  little  below  the  base  of  the  skull.  It  runs 
obliquely  downwards,  forwards,  and  medially,  deep  to  both  carotid  arteries, 
and  pierces  the  thyreo-hyoid  membrane  at  the  posterior  border  of  the  thyreo- 
hyoid  muscle.  It  supplies  the  mucous  membrane  of  the  larynx  and  recessus 
piriformis.  Section  of  one  internal  laryngeal  nerve  renders  the  mucous 
membrane  of  that  half  of  the  larynx  insensitive,  but  should  both  nerves  be 
cut,  inhalation  pneumonia  is  likely  to  supervene  owing  to  the  loss  of  the 
cough  reflex. 

After  opening  the  thyreo-hyoid  membrane,  the  surgeon  cuts 
upwards  and  backwards,  through  the  underlying  pad  of  fat, 
and  divides  the  ligament  which  attaches  the  epiglottis  to  the 
hyoid  bone.  Above  the  ligament  lie  the  submucous  tissue 
and  mucous  membrane  of  the  valleculae,  and  when  these  have 
been  incised  the  epiglottis  can  be  pierced  by  a  strong  silk  ligature 
and  dragged  out  through  the  wound.  This  proceeding  brings 
the  vestibule  of  the  larynx  directly  to  the  surface,  and  affords 
excellent  exposure  of  the  area. 

Cut  Throat. — The  commonest  sites  of  the  wound  in  "  cut 
throat  "  are  immediately  above  and  below  the  hyoid  bone.  By 
throwing  back  his  head  while  he  makes  the  wound,  the  suicide 
unconsciously  protects  the  main  vessels  from  danger,  as  the 
action  retracts  the  carotid  sheath  and  its  contents  more  deeply 
under  cover  of  the  sterno-mastoid.  The  supra-hyoid  incision 
cuts  through  the  mylo-hyoids,  genio-hyoids,  hyo-glossi,  and 


i6o 


THE  HEAD  AND  NECK 


Septal  cartilage 


Perpendicular  lamina  of  ethmoid 

Vomer 

Splienoidal  air  sinus 

Opening  of  auditory  (Eustachian)  tube 
Torus  tubarius  (Eustachian  cushion) 


Mylo-hyoid    - 
Investing  layer  of  deep 
cervical  fascia 
Submental  lymph  gland 


Thyreoid  cartilage 

Lamina  of  cricoid  cartilage 

Pretracheal  fascia 


FIG.  50. — Median  Section  through  Head  and  Neck.  A  tuberculous  abscess 
is  depicted,  originating  in  the  body  of  the  second  cervical  vertebra  and 
descending  behind  the  prevertebral  fascia. 


THE  NECK  161 

genio-glossi,  and  if  it  begins  sufficiently  far  back  it  emerges 
through  the  dorsum  of  the  base  of  the  tongue.  The  lingual 
vessels  and  hypoglossal  nerve  are  divided,  but  the  lingual  nerve 
usually  escapes  as  it  lies  above  the  level  of  the  wound.  More 
posteriorly,  the  external  maxillary  (facial)  artery  and  common 
facial  vein — which  is  usually  the  first  large  vessel  to  be  severed — 
are  reached,  but  the  carotid  sheath  is  only  injured  when  the 
incision  is  a  very  large  one. 

The  infra-hyoid  wound  closely  resembles  the  incision  for 
sub-hyoid  pharyngotomy  (p.  159).  Laterally,  it  cuts  through 
the  superior  thyreoid  artery  and  internal  laryngeal  nerve  before 
reaching  the  sterno-mastoid  and  the  carotid  sheath.  The 
epiglottis  is  apt  to  be  divided,  and  when  it  is  cut  its  upper  part 
may  cause  respiratory  obstruction. 

"  Cut  throat  "  wounds  through  or  below  the  thyreoid  car- 
tilage are  by  no  means  common. 

The  crico-thyreoid  muscle  arises  from  the  side  of  the  cricoid 
cartilage,  and  passes  upwards,  backwards,  and  laterally,  to  be 
attached  to  the  thyreoid  cartilage.  When  the  crico-thyreoid 
contracts  it  elevates  the  anterior  part  of  the  cricoid  cartilage, 
as  the  thyreoid  is  held  firmly  in  place  by  the  sterno-thyreoid  and 
thyreo-hyoid  muscles.  This  movement  depresses  the  posterior 
part  of  the  cricoid  together  with  the  arytenoids,  and  thus 
separates  the  posterior  from  the  anterior  attachment  of  the  vocal 
folds,  rendering  them  tense.  The  external  laryngeal  nerve, 
which  supplies  the  muscle,  is  a  branch  of  the  superior  laryngeal 
(p.  159),  and  lies  in  close  relation  to  the  upper  pole  of  the  lateral 
lobe  of  the  thyreoid  gland.  Should  the  nerve  be  stimulated  by 
the  pressure  of  forceps  during  operations  in  its  neighbourhood, 
the  resulting  muscular  response  may  be  so  strong  as  to  cause 
spasm  of  the  glottis. 

The  condition  of  laryngismus  stridulus  is  due  to  reflex  stimu- 
lation of  the  external  laryngeal  nerve.  It  may  be  caused  by 
direct  pressure  on  the  main  trunk  of  the  vagus  itself  from 
tuberculous  abscesses  or  enlarged  lymph  glands  in  the  thorax. 
Spasm  of  the  glottis  may  also  occur  in  gastric  disorders,  in  which 
case  the  afferent  impulse  travels  along  the  vagus  itself,  and  in 
the  disturbance  due  to  dentition,  when  the  afferent  impulse  is 
carried  up  to  the  sensory  nucleus  of  the  trigeminal,  from  which 
it  spreads  to  the  motor  nucleus  of  the  vagus. 

As  the  two  crico-thyreoid  muscles  diverge  from  each  other 
the  crico-thyreoid  ligament  (middle  part  of  crico-thyreoid 

11 


162  THE  HEAD  AND  NECK 

membrane)  is  exposed  in  the  interval  between  them.  Through 
this  area  the  surgeon  performs  the  operation  of  laryngotomy, 
which  may  be  carried  out  as  an  emergency  operation  when 
some  foreign  body  lodges  in  the  larynx,  or  as  a  preliminary  step 
in  extensive  operations  on  the  jaws  or  mouth.  The  incision  is 
vertical  as  it  passes  through  the  superficial  structures,  but  the 
actual  opening  in  the  ligament  is  made  transversely.  In  this 
way  injury  to  the  crico-thyreoid  artery  is  avoided,  and  the 
cartilages  can  be  separated  widely  to  facilitate  the  introduction 
of  the  laryngotomy  tube.  Unlike  a  tracheotomy  tube,  which  is 
circular  on  section,  a  laryngotomy  tube  is  oval  so  as  to  fit  accur- 
ately into  the  narrow  gap  between  the  cricoid  and  thyreoid 
cartilages.  Laryngotomy  is  not  performed  in  children  owing 
to  the  extreme  narrowness  of  the  crico-thyreoid  ligament. 

In  the  operation  of  Thyreotomy,  or  splitting  of  the  thyreoid 
cartilage,  great  care  must  be  exercised  to  avoid  injuring  the 
vocal  folds.  The  operation  is  performed  through  a  vertical 
median  incision,  which  passes  between  the  depressor  muscles  of 
the  hyoid  and  the  anterior  jugular  veins  of  the  two  sides.  A 
small  opening  is  made  in  the  crico-thyreoid  ligament  above  the 
crico-thyreoid  artery,  and  the  thyreoid  cartilage  is  split  with 
scissors.  In  advanced  age,  calcification  of  the  cartilage  may 
render  the  use  of  a  Gigli  saw  necessary.  It  is  introduced  below, 
and  passed  up  through  the  rima  glottidis  and  brought  out  through 
a  second  small  opening  in  the  thyreo-hyoid  membrane. 

Laryngectomy. — In  excision  of  the  larynx  the  best  approach 
is  obtained  by  a  median  incision,  which  commences  at  the  hyoid 
bone,  and  is  carried  downwards  beyond  the  isthmus  of  the 
thyreoid  gland.  A  short  transverse  incision  is  made  at  each  end, 
and  two  flaps,  consisting  of  skin,  superficial  fascia,  and  platysma, 
are  turned  laterally.  The  superficial  layer  of  depressor  muscles 
(p.  154)  is  divided,  and  the  sterno-thyreoid  is  cut  across  low 
down.  This  procedure  exposes  the  thyreoid  gland  below  and 
on  each  side  of  the  larynx.  The  pretracheal  fascia  is  incised 
along  the  medial  border  of  the  upper  pole  of  the  gland  on  each 
side,  and  the  isthmus  is  divided  between  ligatures.  In  this 
part  of  the  operation  the  superior  thyreoid  arteries  (p.  167)  must 
be  carefully  preserved.  The  gland  can  now  be  separated  from 
the  larynx  and  the  trachea,  which  is  exposed  lying  on  the 
anterior  surface  of  the  oesophagus.  The  trachea  is  separated 
from  the  oesophagus  by  blunt  dissection  as  high  up  as  the  lower 
border  of  the  inferior  constrictor.  The  recurrent  (laryngeal) 


THE  NECK  163 

nerve  and  the  inferior  laryngeal  artery  pass  upwards  under  cover 
of  the  muscle,  and  may  be  divided  at  this  stage.  The  trachea 
is  cut  through  near  the  cricoid  cartilage,  and  its  lower  end  is 
turned  forwards  and  stitched  to  the  lower  margin  of  the  skin 
incision,  since  it  tends  to  retract  into  the  thorax. 

The  larynx  is  next  retracted  upwards  and  forwards,  and  the 
inferior  constrictor  and  the  stylo -pharyngeus  are  divided.  In 
separating  the  larynx  from  the  lower  part  of  the  pharynx, 
care  must  be  taken  not  to  "  button-hole  "  the  mucous  membrane 
on  the  posterior  aspect  of  the  cricoid  (p.  189).  At  the  upper 
border  of  the  cricoid  the  pharynx  is  opened,  and  the  epiglottis 
may  be  cut  across  if  it  is  not  involved.  The  larynx  is  now  only 
fixed  above  and  in  front.  The  thyreo-hyoid  muscle  and  mem- 
brane are  divided,  and  the  cut  is  carried  backwards  through  the 
subjacent  pad  of  fat  till  the  divided  epiglottis  is  reached.  After 
division  of  the  internal  laryngeal  nerve  and  its  accompanying 
artery  the  larynx  can  be  removed.  If  the  epiglottis  is  involved 
in  the  disease,  the  latter  part  of  the  operation  follows  the  course 
of  a  sub-hyoid  pharyngotomy. 

The  Trachea  begins  immediately  below  the  cricoid  car- 
tilage, and  ends  opposite  the  lower  border  of  the  fourth  thoracic 
vertebra  by  dividing  into  the  two  bronchi.  It  is  about  4^  inches 
long,  and  its  diameter  varies  from  f  inch  to  one  inch.  The 
cervical  part  of  the  trachea  is  2|  inches  long,  and  as  it  descends 
it  becomes  more  deeply  placed,  so  that  at  the  upper  border  of  the 
manubrium  sterni  it  lies  i|  inches  from  the  surface.  In  children 
of  from  three  to  five  years  of  age  the  cervical  part  of  the 
trachea  is  ij  inches  long  and  only  £  inch  wide.  These 
measurements  give  some  indication  of  the  variations  necessary 
in  the  diameters  of  tracheotomy  tubes. 

The  trachea  is  freely  movable,  since  it  is  surrounded  by  loose 
cellular  tissue,  and  when  necessary  it  can  be  retracted  to  one  or 
other  side  without  much  difficulty.  The  isthmus  of  the  thyreoid 
gland  lies  in  front  of  the  second,  third,  and  fourth  rings  of  the 
trachea,  while  the  lateral  lobes  lie  one  on  each  side  in  relation 
to  the  upper  six  rings  and  to  the  cricoid  and  thyreoid  cartilages. 

The  posterior  surface  of  the  trachea,  which  is  in  contact 
with  the  oesophagus,  is  flattened  so  that  the  tube  is  horseshoe- 
shaped  on  section.  This  is  due  to  a  deficiency  in  the  cartilagin- 
ous rings  posteriorly.  The  posterior  wall  consists  of  the  mucous 
membrane  and  the  fibro-elastic  coat  of  the  trachea.  If  the 
surgeon,  in  performing  tracheotomy,  opens  the  trachea  too 


164  THE  HEAD  AND  NECK 

vigorously,  he  may  slit  the  posterior  wall  and  open  into  the 
subjacent  oesophagus. 

The  operation  of  High  Tracheotomy  is  performed  through 
the  interval  between  the  cricoid  cartilage  and  the  isthmus  of  the 
thyreoid  gland.  It  is  usually  carried  out  for  some  form  of 
laryngeal  obstruction,  and  has  been  labelled  an  "  emergency  " 
operation.  There  is,  however,  no  necessity  for  excessive  hurry, 
because,  provided  that  the  patient  is  not  further  embarrassed 
by  the  administration  of  a  totally  unnecessary  anaesthetic, 
respiration  can  always  be  restarted  after  the  trachea  is  opened. 
During  the  operation  the  neck  is  well  extended  over  a  small 
sandbag  or  cushion,  and  is  held  in  position  in  the  middle  line 
by  an  assistant  until  the  tracheotomy  tube  has  been  inserted. 
In  this  way  the  trachea  is  steadied  and  drawn  tight,  for  its 
rounded  shape  renders  it  liable  to  be  pushed  aside,  especially 
if  the  head  is  not  held  absolutely  in  the  middle  line,  in  which 
event  the  oesophagus  may  be  opened  by  mistake.  The  incision 
may  be  either  vertical  or  horizontal  as  it  divides  the  skin  and 
superficial  fascia,  but  it  should  pass  vertically  between  the  two 
anterior  jugular  veins.  On  account  of  the  obstruction  to 
respiration  these  veins  are  engorged  and  may  almost  touch  one 
another.  The  investing  layer  of  the  deep  fascia  is  incised  vertic- 
ally, and  if  the  subjacent  sterno-hyoids  are  close  together  they 
must  be  retracted.  The  surgeon  now  feels  for  the  cricoid 
cartilage  and  the  isthmus  of  the  thyreoid  gland,  and  when  these 
guides  have  been  identified  he  makes  a  transverse  cut  through 
the  pretracheal  fascia  just  below  the  cricoid  cartilage.  The 
isthmus  of  the  thyreoid  gland,  with  its  fascial  sheath  derived 
from  the  pretracheal  fascia,  can  now  be  retracted  downwards, 
exposing  the  upper  rings  of  the  trachea.  A  vertical  incision  is 
then  made  in  the  exposed  part  of  the  trachea  from  below  up- 
wards, the  back  of  the  knife  being  directed  to  the  isthmus  of  the 
thyreoid  gland  to  avoid  injuring  the  anastomosing  terminal 
branches  of  the  superior  thyreoid  arteries  on  its  upper  border. 
If  sufficient  room  is  not  obtained  by  this  method,  the  cricoid 
cartilage  may  be  divided,  or  the  isthmus  of  the  thyreoid  gland 
may  be  cut  through.  It  is  said  (Treves)  that  there  is  no  danger 
of  thyreoidism  by  absorption  from  the  unligated  portions  of 
the  gland.  When  the  tube  is  inserted  care  must  be  taken  not 
to  pass  it  down  the  outside  of  the  trachea  amongst  the  depressor 
muscles  nor  between  the  fibro -elastic  membrane,  in  which  the 
cartilaginous  rings  are  embedded,  and  the  mucous  lining. 


THE  NECK  165 

Low  Tracheotomy  is  usually  performed  to  relieve  dyspnoea 


Digastric, 
anterior  belly 


Thyreo-hyoid 

membrane 


Thyreoid    _ 
cartilage 
Thyreo-hyoid 


Stcrno-hyoid 


Cr 

cart 


Anterior 
jugular  vein 


Fascia  enclosing 
suprasternal  space 


Pretracheal  fascia, 
cut  to  show  forma- 
tion of  sheath  of 
thyreoid  gland 


'•*•     Sterno-mastoid 


Connection  between  anterior  jugular  veins 

FIG.  51. — The  Anterior  Median  Line  of  the  Neck.  On  the  left  side  the 
platysma  has  been  removed,  and  the  sterno-hyoid  and  sterno-thyreoid 
have  been  partially  resected. 

produced  by  malignant  disease  of  the  thyreoid  gland.      In  this 

11  a 


i66  THE  HEAD  AND  NECK 

operation  the  trachea  is  opened  below  the  isthmus  of  the  thyreoid 
gland,  and  the  wound  will  necessarily  be  deep,  as  this  part  of 
the  trachea  lies  at  some  distance  from  the  surface.  On  this 
account  the  skin  incision  must  be  a  long  one,  and  it  should 
extend  down  to  the  jugular  (supra-sternal)  notch  or  on  to  the 
sternum.  It  is  vertical  in  direction,  and  passes  through  Burns's 
space  (p.  in).  In  the  cellular  tissue  which  occupies  the  space, 
the  communicating  branch  between  the  two  anterior  jugular 
veins  must  be  found  (Fig.  51),  ligatured,  and  divided.  The 
posterior  wall  of  the  space  is  then  cut  through  and  a  collection 
of  loose  fat  is  encountered.  In  this  fat,  which  also  contains  a 
few  lymph  glands,  the  inferior  thyreoid  veins  descend  in  front 
of  the  trachea  from  the  lower  and  medial  surfaces  of  the  lateral 
lobes  of  the  thyreoid  gland.  The  veins  of  the  two  sides  may 
unite  and  join  the  left  innominate  vein,  or  they  may  open 
separately  into  the  right  and  left  innominate  veins.  When 
present,  the  thyreoidea  ima  artery  ascends  in  this  fat  from  the 
innominate  artery  to  the  lower  border  of  the  isthmus  of  the 
thyreoid  gland.  All  these  vessels  may  require  to  be  tied  before 
the  pretracheal  fascia  is  divided.  The  trachea  is  then  incised 
from  belowr  upwards  lest  any  injury  be  done  to  the  left  innominate 
vein  or  the  innominate  artery,  which  sometimes  occupy  a  higher 
position  than  usual. 

In  children  low  tracheotomy  may  be  rendered  very  difficult 
owing  to  the  shortness  of  the  neck  and  the  presence  of  the 
thymus  gland.  Further,  the  position  of  the  innominate  artery 
and  the  left  innominate  vein  is  slightly  higher  than  in  the  adult. 
The  Thymus  Gland  is  of  considerable  size  in  the  fcetus ; 
it  undergoes  little  alteration  in  size  during  childhood,  but  there- 
after it  undergoes  almost  complete  atrophy.  It  is  enclosed  in 
a  fascial  sheath  and  lies  in  the  superior  mediastinum,  in  front 
of  the  trachea  and  great  vessels,  and  immediately  behind  the 
manubrium  sterni.  Recent  observations  tend  to  show  that  in 
the  infant  certain  obscure  conditions,  which  are  associated  with 
dyspnoea  and  stridor,  are  due  to  hypertrophy  of  the  thymus 
gland,  and  the  operation  of  subtotal  subcapsular  thymectomy  has 
been  performed  successfully  in  several  cases. 

The  method  of  approach  is  the  same  as  that  employed  in 
low  tracheotomy.  The  gland  is  found  behind  the  posterior 
wall  of  Burns's  space,  and  one  lobe  may  be  shelled  out  from  its 
sheath  by  blunt  dissection. 

The  Thyreoid  Gland  consists  of  an  isthmus  and  two  lateral 


THE  NECK  167 

lobes.  The  position  and  relations  of  the  isthmus  are  referred 
to  on  p.  163.  Each  lateral  lobe  is  conical  in  shape ;  the  broad 
base  extends  downwards  as  far  as  the  sixth  ring  of  the  trachea, 
and  the  apex  passes  upwards  on  to  the  lamina  of  the  thyreoid 
cartilage.  The  medial  surface  of  the  lateral  lobe  is  closely 
applied  to  the  trachea  and  larynx,  in  front,  and  to  the  cesophagus 
and  pharynx,  behind.  Postero-laterally  the  gland  is  in  contact 
with  the  carotid  sheath,  while  its  antero-lateral  surface  lies 
under  cover  of  the  depressor  muscles  of  the  hyoid  bone  (Fig.  36). 
Sometimes  an  additional  lobe — the  pyramidal  lobe — is  present. 
It  ascends  from  the  upper  border  of  the  isthmus  on  one  or  other 
side  of  the  median  plane,  and  it  may  be  attached  to  the  hyoid 
bone  by  a  fibre-muscular  slip,  termed  the  levator  glandulse 
thyreoideae. 

The  pretracheal  fascia  invests  the  gland  with  &  fibrous  sheath, 
which  is  thickest  on  its  deep  and  postero-lateral  aspects,  and  is 
very  adherent  to  the  trachea  behind  the  isthmus.  The  gland 
can  easily  be  separated  from  its  sheath,  save  on  the  posterior 
aspect  of  the  isthmus  where  the  two  are  intimately  connected. 
In  addition  to  its  loose  fascial  sheath,  the  gland  is  provided 
with  a  complete  fibrous  capsule,  which  envelops  it  closely,  and 
sends  in  numerous  fibrous  septa  to  separate  the  lobules  and  acini 
from  one  another.  The  numerous  blood-vessels  of  the  gland 
run  in  the  fibrous  septa,  and  are  brought  into  close  contact  with 
the  outer  aspects  of  the  acini. 

The  blood-supply  of  the  thyreoid  gland  is  derived  from  the 
superior  and  inferior  thyreoid  arteries  (pp.  121, 143).  The  former 
is  mainly  distributed  to  the  medial  surface  of  the  upper  pole  of 
the  lateral  lobe  and  to  the  isthmus  ;  the  latter  supplies  the 
lower  pole  and  lateral  surface.  Both  arteries  pierce  the  fascial 
sheath  posteriorly,  and  are  then  associated  with  the  parathyreoid 
glands  (p.  169). 

In  the  operation  of  Thyreoidectomy  it  is  advantageous 
to  have  the  patient's  head,  neck,  and  thorax  on  a  slight  upward 
incline  in  order  to  diminish  the  haemorrhage.  Kocher's  collar 
incision  or  the  angular  incision  may  be  employed,  and  both  give 
good  access  to  the  gland.  The  angular  incision  begins  on  the 
posterior  border  of  the  sterno-mastoid  at  the  level  of  the  hyoid 
bone,  passes  downwards  and  medially  to  the  cricoid  cartilage, 
and  is  then  carried  vertically  downwards  in  the  median  line  to 
the  jugular  (supra-sternal)  notch.  In  the  upper  part  of  the  wound 
the  incision  is  deepened  through  the  superficial  fascia  and  the 

116 


168  THE  HEAD  AND  NECK 

platysma,  and,  after  the  external  jugular  vein  has  been  dealt 
with,  the  flap  is  undercut  and  turned  downwards  and  laterally. 
The  investing  layer  of  the  deep  cervical  fascia  is  divided  vertically 
between  the  anterior  jugular  veins,  which  are  both  secured,  and 
the  depressor  muscles  of  the  hyoid  are  then  identified.  Some- 
times the  muscles  are  spread  out  in  a  thin  sheet  over  the  tumour, 
and  the  recognition  of  their  edges  may  offer  some  difficulty. 
The  sterno-hyoid  and  the  omo-hyoid  are  divided  high  up  to 
preserve  their  nerve-supply,  and  in  such  a  way  that  they  can  be 
reunited  at  a  later  stage.  The  sterno-thyreoid,  which  is  now 
exposed,  is  carefully  raised  from  the  surface  of  the  gland  so  as 
to  avoid  injuring  the  superior  and  the  middle  thyreoid  veins 
(p.  119);  and  it  is  then  cut  across.  The  thyreoid  veins  are  now 
doubly  ligatured  and  divided  lest  they  should  be  torn  during 
the  subsequent  manipulations.  The  incision  is  deepened  in 
the  median  line  between  the  two  sterno-thyreoids,  and  passes 
through  the  pretracheal  fascia,  which  forms  the  loose  fascial 
sheath  of  the  gland.  The  surgeon  can  now  introduce  a  finger 
into  the  space  between  the  sheath  and  the  true  capsule  of  the 
gland.  This  space  is  crossed  by  the  thyreoid  veins  and  arteries. 
The  surgeon  next  ligatures  the  superior  thyreoid  artery  within 
the  sheath,  and  in  this  way  the  external  laryngeal  nerve,  which 
is  associated  with  the  artery  outside  the  sheath,  cannot  be 
injured.  The  upper  pole  of  the  gland  can  now  be  brought  up 
into  the  wound,  and  the  isthmus  is  divided,  after  it  has  been 
separated  from  the  adhesions  which  bind  it  to  the  sheath.  The 
tumour  is  now  more  movable,  and  by  turning  the  lateral  lobe 
forwards  and  medially,  the  inferior  thyreoid  artery  may  be 
secured  within  the  sheath  and  close  to  the  gland.  If  the  sheath 
is  left  intact  postero-medially,  the  recurrent  (laryngeal)  nerve, 
which  crosses  the  artery  in  this  situation,  will  not  be  seen,  since 
it  lies  outside  the  fascial  sheath  (Fig.  36). 

The  thyreoid  gland  normally  follows  the  movements  of  the 
trachea  in  swallowing,  but  when  it  is  the  site  of  malignant  disease 
it  becomes  adherent  to  the  surrounding  structures  and  fails  to 
do  so.  This  fixation  of  the  thyreoid  gland  may  also  be  produced 
by  syphilitic  adhesions  following  a  broken-down  gumma. 

Simple  tumours  of  the  thyreoid  gland  rarely  give  rise  to  any 
irritation  of  the  recurrent  nerve,  but  malignant  tumours  frequently 
do  so.  Both  varieties  may  cause  severe  dyspnoea  by  direct 
pressure  on  the  trachea.  Thyreoid  tumours  may  displace  the 
carotid  sheath  and  its  contents  laterally  into  the  posterior 


THE  NECK  169 

triangle,  or  they  may  enlarge  in  a  downward  direction  and 
pass  through  the  thoracic  inlet  (intra-thoracic  variety). 

Adenomata  or  solitary  cysts  of  the  thyreoid  gland  may  be 
removed  by  enucleation.  In  this  operation  the  capsule  and 
the  gland  substance  are  incised  until  the  wall  of  the  cyst  or 
adenoma  is  reached,  and  the  tumour  is  then  removed  by  blunt 
dissection,  together  with  the  thinned-out  portions  of  glandular 
tissue  and  sheath  which  lie  superficial  to  it. 

Loss  of  the  thyreoid  secretion  during  childhood,  either  from 
atrophy  or  congenital  absence  of  the  gland,  leads  to  the  condition 
of  cretinism,  while  atrophy  or  complete  removal  of  the  gland  in 
adult  life  causes  myxcedema. 

The  Parathyreoid  Glands  are  small  pea -like  structures, 
two  on  each  side,  which  lie  normally  on  the  posterior  aspect 
of  the  lateral  lobes  of  the  thyreoid  gland,  and  are  most 
commonly  found  embedded  in  its  fibrous  capsule.  The 
removal  of  all  of  these  bodies  leads  to  tetany  and  death. 
Consequently,  in  total  removal  of  the  thyreoid  gland,  which 
is  only  performed  for  malignant  disease,  great  care  is  exercised 
to  leave  some  of  the  parathyreoids  intact.  They  can  usually 
be  identified  by  their  close  relation  to  an  anastomosing 
vessel  which  connects  the  superior  and  inferior  thyreoid 
arteries  on  the  posterior  aspect  of  the  lateral  lobe  of  the 
gland. 

Development  of  the  Thyreoid  Gland. — The  thyreoid  gland 
arises  as  a  median  diverticulum  of  the  entoderm  of  the  floor  of 
the  primitive  pharynx,  and  grows  tailwards  in  the  interval 
behind  the  tuberculum  impar  (p.  193).  In  doing  so  it  passes 
ventral  to  the  cartilages  of  the  second  to  the  sixth  visceral  arches. 
At  first  a  hollow  bud,  the  thyreoid  rudiment  soon  becomes  solid, 
and  enlarges  to  form  the  isthmus  and  lateral  lobes  of  the  gland. 
Its  connection  with  the  floor  of  the  mouth,  which  is  termed  the 
thyreo-glossal  duct,  gradually  disappears,  and  the  foramen  caecum 
on  the  dorsum  of  the  tongue  is  all  that  normally  remains  of  its 
upper  end.  The  pyramidal  lobe  and  the  levator  glandulse 
thyreoidese  are  derived  from  its  lower  end. 

Occasionally  the  thyreo-glossal  duct  is  found  embedded  in 
the  hyoid  bone.  It  is  probable  that  in  these  cases  the  diver- 
ticulum passed  behind  the  cartilage  of  the  second  but  in  front 
of  the  cartilage  of  the  third  arch,  and  was  caught  between  them 
when  they  fused  to  form  the  body  of  the  bone  (p.  149).  Abnormal 
remains  of  the  duct  may  form  thyreo-glossal  cysts  and  tumours. 


i  yo  THE  HEAD  AND  NECK 

The  parathyreoid  glands  are  derived  from  the  entoderm 
lining  the  third  and  fourth  visceral  pouches  (p.  149). 

Thyreo-glossal  Cysts  or  tumours  may  arise  in  the  lingual 
or  cervical  part  of  the  duct.  In  the  former  case  they  lie  between 
the  genio-glossi  (p.  148) ;  in  the  latter  they  are  median,  and 
lie  superficial  to  the  thyreoid  or  cricoid  cartilage.  Recurrence 
of  the  condition  is  certain  if  any  procedure  short  of  complete 
excision  is  attempted.  The  operation  may  be  one  of  great  diffi- 
culty, as  it  frequently  entails  a  dissection  right  up  to  the  foramen 
caecum.  The  procedure  is  similar  to  that  already  described  for 
the  removal  of  a  branchial  fistula,  but  it  is  advisable  to  resect 
the  central  portion  of  the  hyoid  bone  lest  some  of  the  germinal 
cells  of  the  tract  are  embedded  in  it  (p.  169).  Recurrence  of 
the  condition  due  to  neglect  of  this  important  detail  is  now  a 
well-recognised  possibility  (Stiles). 


THE  FACE,  MOUTH  AND  PHARYNX 

Bony  Landmarks. — At  the  junction  of  the  intermediate 
and  medial  thirds  of  the  upper  margin  of  the  orbit  the  supra- 
orbital  notch  can  be  examined,  and  the  supra-orbital  nerve, 
which  it  transmits,  can  be  rolled  against  the  bone.  The  super- 
ciliary arch  (ridge)  lies  just  above  the  upper  margin  of  the  orbit 
and  is  more  prominent  medially.  In  the  middle  line  the  two 
arches  are  united  by  an  elevation,  the  glabella  ;  it  lies  a  little 
above  the  nasion,  a  depression  at  the  root  of  the  nose,  which 
indicates  the  naso-frontal  suture.  If  the  nasal  bones  are  traced 
downwards  in  the  median  line,  their  union  with  the  nasal  car- 
tilages will  be  recognised  by  a  slight  depression,  and  on  each 
side  of  the  nose  at  this  level  the  margins  of  the  apertura  piri- 
formis  (osseous  anterior  nares)  can  be  felt.  The  anterior  nasal 
spine  is  recognised  by  placing  the  finger  on  the  middle  of  the 
upper  lip  and  pressing  upwards  against  the  nasal  septum. 

The  zygomatic  process  of  the  temporal  bone  runs  forwards 
from  the  tragus  to  articulate  with  the  zygomatic  (malar)  bone, 
forming  the  zygomatic  arch.  Below  the  anterior  part  of  the  arch 
the  fingers  can  be  inserted  into  the  infra-temporal  (zygomatic) 
fossa,  but  the  temporal  fascia,  which  is  attached  to  the  upper 
border  of  the  arch,  is  so  dense  that  the  temporal  fossa  cannot  be 
explored  in  the  same  way.  The  tubercle  of  the  zygomatic 
(malar)  bone  is  felt  when  the  upper  border  of  the  arch  is  traced 


THE  FACE,  MOUTH  AND  PHARYNX  171 

forwards  and  upwards,  and  half  an  inch  above  it  the  zygomatic 
process  (external  angular  process)  of  the  frontal  bone  is  en- 
countered. The  pre-auricular  point  is  situated  on  the  zygomatic 
process  of  the  temporal  bone  immediately  in  front  of  the  tragus. 
Here  the  superficial  temporal  vessels  can  be  compressed  against 
the  bone  as  they  cross  the  zygomatic  arch. 

Immediately  in  front  of  the  tragus  and  below  the  root  of 
the  zygomatic  process  of  the  temporal  bone  the  condyle  of  the 
mandible  can  be  made  out,  and  when  the  mouth  is  opened  it 
slides  forwards  so  that  the  finger  can  be  inserted  into  the  hollow 
of  the  mandibular  fossa.  If  the  finger  is  placed  immediately 
below  the  zygomatic  bone  the  coronoid  process  impinges  on  it 
when  the  mouth  is  opened,  and  it  can  be  traced  downwards  into 
the  anterior  border  of  the  ramus  of  the  mandible.  The  coronoid 
process  can  also  be  examined  from  the  inside  of  the  mouth,  and 
the  tense  band  of  the  ptery  go -mandibular  raphe  (p.  176)  is  felt 
on  its  medial  side.  The  posterior  border  of  the  ramus,  though 
masked  above  by  the  parotid  gland,  can  be  felt  through  the  skin, 
but  its  outer  surface  is  completely  covered  by  the  masseter. 
The  angle  and  outer  surface  of  the  body  of  the  mandible  are  palpable 
through  their  coverings,  and  with  one  finger  outside  and  another 
inside  the  mouth  it  is  possible  to  estimate  the  thickness  of  the 
bone  and  to  recognise  any  thickening  or  irregularity.  Near  the 
lower  border  of  the  symphysis,  and  on  its  inner  aspect,  the  mental 
spine  (genial  tubercles)  may  be  felt  by  pressing  upwards  through 
the  apex  of  the  submental  triangle. 

A  line  drawn  from  the  supra-orbital  notch  to  the  lower  border 
of  the  mandible  so  as  to  pass  between  the  two  lower  premolars 
will  cross  the  infra-orbital  foramen  a  quarter  of  an  inch  below 
the  lower  margin  of  the  orbit.  It  also  passes  through  the  mental 
foramen,  which  usually  (depending  on  the  age  of  the  subject) 
lies  midway  between  the  upper  and  lower  borders  of  the 
mandible. 

The  Skin  of  the  Face  possesses  numerous  sebaceous  and 
sweat  glands,  and  lies  in  intimate  relationship  with  the  sub- 
jacent loose  connective  tissue,  in  which  the  muscles  of  facial 
expression  are  embedded.  The  absence  of  deep  fascia  from  the 
face  allows  muscles  arising  from  bone  to  be  inserted  directly 
into  the  skin,  which  is  therefore  freely  movable.  Further,  the 
laxity  of  the  cellular  connective  tissue,  which  is  unsupported  by 
deep  fascia,  facilitates  the  rapid  spread  of  oedema  over  large 
areas.  Over  the  nose,  however,  the  skin  is  firmly  bound  down 


1 72  THE  HEAD  AND  NECK 

to  the  subjacent  cartilage,  and  inflammation  in  this  region  is 
acutely  painful. 

Excellent  results  are  obtained  from  plastic  operations  on 
the  face,  as  the  skin  can  easily  be  stretched  while  still  in  contact 
with  the  underlying  connective  tissue.  This  latter  is  well 
supplied  with  blood-vessels,  and  hence  the  vitality  of  the  skin 
is  not  affected. 

Cutaneous  Nerves.— The  whole  of  the  skin  of  the  face,  with 
the  exception  of  an  area  over  the  angle  of  the  mandible,  is 
supplied  by  the  three  divisions  of  the  trigeminal  nerve.  The 
ophthalmic  nerve  supplies  most  of  the  area  derived  from 
the  fronto-nasal  process  (p.  191),  the  (superior)  maxillary  nerve 
supplies  the  area  derived  from  the  maxillary  process,  and 
the  mandibular  (inferior  maxillary)  that  from  the  mandibular 
arch. 

The  supra-trochlear  and  supra-orbital  nerves  arise  from  the 
frontal  branch  of  the  ophthalmic  and  leave  the  orbit  at  its  upper 
margin.  The  former  is  the  more  medial,  and  supplies  a  small 
area  of  the  skin  of  the  forehead.  The  latter  emerges  through 
the  supra-orbital  notch,  accompanied  by  the  supra-orbital 
branch  of  the  ophthalmic  artery,  and  supplies  the  skin  of  the 
forehead  and  the  front  of  the  scalp.  This  nerve  may  require 
to  be  divided  in  cases  of  severe  neuralgia.  An  incision  is  made 
through  the  eyebrow  immediately  over  the  notch  and  is  carried 
down  to  the  pericranium.  In  this  way  the  nerve  is  at  once 
divided;  but,  to  prevent  regeneration,  the  proximal  portion 
is  found  by  separating  the  lower  edge  of  the  wound  from  the 
pericranium,  and  a  piece  of  it  is  resected  as  it  enters  the  flap 
close  to  the  notch. 

The  terminal  branches  of  the  lacrimal  division  of  the 
ophthalmic  nerve  supply  the  skin  and  subjacent  conjunctiva 
of  the  lateral  part  of  the  upper  eyelid. 

The  terminal  branches  of  the  naso-ciliary  (nasal)  division 
of  the  ophthalmic  nerve  appear  on  the  face  as  the  infra-trochlear 
and  external  nasal  nerves  (Fig.  52). 

Branches  of  the  infra-orbital  nerve,  which  is  the  terminal 
portion  of  the  maxillary,  supply  the  lower  eyelid,  the  side  of 
the  nose  and  the  cheek  adjoining  it,  and  the  upper  lip.  Severe 
neuralgia,  radiating  over  the  areas  indicated,  is  not  uncommon, 
and  the  infra-orbital  nerve  may  be  exposed  by  a  horizontal 
incision  just  below  the  infra-orbital  margin  and  above  the  fora- 
men of  the  same  name.  The  incision  is  carried  down  to  the 


THE  FACE,  MOUTH  AND  PHARYNX 


periosteum;  and  its  lower  border  is  separated  downwards  by  blunt 
dissection.  In  this  way  the  nerve  is  found  as  it  leaves  the  canal. 
If  the  neuralgia  affects  the  teeth  and  gums  of  the  maxilla,  the 
proximal  portion  of  the  nerve,  after  division,  must  be  twisted 
out.  When  this  is  done  the  anterior  and  middle  superior 


Auriculo-temporal  nerve 


Supra-orbital  nerve 


Supra-trochlear 
nerve 

Lacrimal  nerve 


Infra-trochlear 
nerve 


Infra-orbital 

nerve 
External 
nasal  nerve 


Buccinator  nerve 
>uccal  nerve 


Mental  nerve 


Parotid  gland 

FIG.  52.— The  Nerves  of  the  Face. 

alveolar  (dental)  branches  are  destroyed,  since  they  arise  from 
the  infra-orbital  nerve  as  it  lies  in  its  canal  in  the  floor  of  the 
orbit. 

The  zygomatico- temporal  (temporal)  and  zygomatico  -facial 
(malar)  are  the  only  other  branches  of  the  maxillary  nerve  which 
appear  on  the  face. 

Three  branches  of  the  mandibular  (inferior  maxillary) 
division  of  the  trigeminal  supply  cutaneous  areas  in  the  face. 


174  THE  HEAD  AND  NECK 

(i)  The  buccinator  (long  buccaT)  nerve  supplies  the  posterior  part 
of  the  cheek,  and  (2)  the  mental  nerve,  which  is  the  terminal 
branch  of  the  inferior  alveolar,  supplies  the  skin  overlying  the 
body  of  the  mandible.  In  severe  neuralgia  the  mental  nerve 
can  be  exposed  by  an  incision  through  the  outer  side  of  the  gum 
just  beneath  the  lower  premolars.  The  lower  part  of  the  wound 
is  retracted  downwards,  and  the  nerve  is  found  as  it  leaves  the 
mental  foramen.  When  the  pain  also  affects  the  gums  and 
teeth  the  nerve  is  twisted  out  in  order  to  destroy,  if  possible, 
the  inferior  dental  plexus  within  the  canal. 

(3)  The  auriculo-temporal  nerve  supplies  the  skin  in  front  of 
the  ear,  and  extends  upwards  to  the  vertex.  In  addition,  it 
supplies  the  skin  of  the  upper  part  of  the  auricle  and  the  integu- 
ment which  lines  the  external  acoustic  meatus  and  covers 
the  membrana  tympani.  On  this  account  foreign  bodies  in 
the  meatus  and  chronic  inflammatory  conditions  of  its  walls 
commonly  cause  referred  pain  over  the  side  of  the  head. 

The  remainder  of  the  auricle  and  the  skin  over  the  angle 
of  the  mandible  are  supplied  by  the  great  auricular  nerve  (C.  2 
and  3). 

Congenital  cutaneous  naevi  on  the  face  ("  port  wine  stains  ") 
map  out  very  accurately  the  areas  supplied  by  one  or  more 
divisions  of  the  trigeminal. 

The  External  Maxillary  (Facial)  Artery  (p.  122)  crosses 
the  inferior  border  of  the  mandible  just  in  front  of  the  masseter 
(i£  inches  from  the  angle  of  the  mandible),  and  its  pulse  can 
readily  be  felt  in  that  situation.  It  then  runs  upwards  and 
forwards  over  the  bone  and  the  buccinator  to  a  point  half  an 
inch  lateral  to  the  angle  of  the  mouth,  and  from  there  to  a  point 
a  little  behind  the  ala  nasi.  Thereafter  it  ascends  to  the  medial 
palpebral  commissure  (inner  canthus),  where  it  anastomoses 
with  the  terminal  branches  of  the  ophthalmic  artery.  In  this 
situation,  therefore,  there  is  an  anastomosis  between  the  internal 
and  external  carotid  arteries.  In  the  lower  part  of  its  course 
the  artery  is  covered  by  the  platysma  and  the  risorius,  which 
blend  with  one  another  in  the  lower  part  of  the  face.  Near  the 
angle  of  the  mouth  it  becomes  quite  superficial,  but  at  a  higher 
level  it  is  crossed  by  the  zygomaticus  and  by  the  muscle  which 
elevates  the  upper  lip.  The  course  of  the  vessel  is  very  tortuous, 
so  that  it  is  not  affected  by  the  free  movements  of  facial 
expression. 

A  free  anastomosis  occurs  between  the  vessels  of  the  two 


THE  FACE,  MOUTH  AND  PHARYNX  175 

sides,  and  in  addition  each  anastomoses  with  the  transverse 
facial  and  middle  temporal  branches  of  the  superficial  temporal 
artery. 

The  superior  and  inferior  labial  (coronary)  branches  supply 
the  lips  and  lie  in  the  submucous  tissue.  During  operations 
on  the  lips,  these  vessels  are  controlled  by  an  assistant,  who 
grasps  the  lip  between  his  finger  and  thumb.  It  should  be 
remembered  that  they  lie  very  close  to  the  muco-cutaneous 
junction. 

The  Anterior  Facial  Vein  descends  from  the  medial 
palpebral  commissure  (inner  canthus),  posterior  to  the  external 
maxillary  artery,  but  its  course  is  much  straighter  than  that  of 
the  artery.  At  its  commencement,  where  it  is  known  as  the 
angular  vein  (p.  220),  it  communicates  with  the  ophthalmic 
veins — and  therefore  indirectly  with  the  cavernous  sinus — and 
it  terminates  by  uniting  with  the  posterior  facial  (p.  176)  to  form 
the  common  facial  vein,  which  joins  the  internal  jugular.  If  it 
is  involved  in  an  acute  infective  process,  such  as  carbuncle, 
septic  thrombosis  with  embolism  may  occur  owing  to  the  absence 
of  valves.  The  condition  may  spread  in  either  direction,  for 
if  there  is  any  obstruction  to  the  downward  flow,  the  direction 
of  the  stream  is  at  once  reversed.  If  it  spreads  upwards  it  may 
cause  thrombosis  of  the  cerebral  sinuses,  but  if  downwards  it 
may  set  free  septic  emboli  into  the  internal  jugular  vein.  Below 
the  zygomatic  bone  and  in  front  of  the  masseter  the  anterior 
facial  vein  communicates  freely  with  the  pterygoid  venous 
plexus,  and  this,  in  its  turn,  communicates  with  the  cavernous 
sinus  through  the  foramen  ovale  and  the  foramen  Vesalii. 
Infection  may  reach  the  cerebral  sinuses  by  this  route,  either 
from  the  anterior  facial  vein  or  from  the  pterygoid  plexus. 

The  Parotid  Gland  occupies  the  interval  between  the 
mastoid  process  and  the  posterior  border  of  the  ramus  of  the 
mandible,  and  its  deep  part  rests  on  the  styloid  process.  It 
is  limited  above  by  the  zygomatic  arch  and  the  external  acoustic 
meatus,  and  below  it  overlaps  the  posterior  belly  of  the  digastric.. 
In  front  it  extends  on  to  the  surface  of  the  masseter  (Fig.  52). 
It  is  completely  enclosed  by  a  fascial  sheath  derived  from  the 
deep  cervical  fascia,  which  sends  fibrous  septa  into  the  gland. 
The  superficial  portion  of  the  sheath  is  extremely  dense  and 
strong,  and  offers  great  resistance  to  any  swelling  of  the  parotid 
or  to  any  enlargement  of  the  lymph  glands  which  lie  embedded 
within  it. 


176  THE  HEAD  AND  NECK 

Branches  of  the  great  auricular  nerve  ramify  over  the  surface 
of  the  sheath,  and  the  auriculo-temporal  nerve  pierces  it  just 
below  the  zygomatic  process  of  the  temporal  bone.  Any  acute 
or  rapidly  growing  swelling  within  the  sheath  will  press  on  these 
nerves  and  give  rise  to  pain,  which  is  referred  to  the  areas  of 
their  distribution.  In  acute  parotitis  examples  of  this  pain  are 
afforded  during  the  activity  of  the  gland  at  meal-times. 

The  facial  nerve,  the  external  carotid  artery,  and  the  posterior 
facial  (temporo-maxillary)  vein  are  all  more  or  less  embedded 
in  the  substance  of  the  gland.  The  nerve  traverses  the  gland 
and  crosses  the  vessels  superficially. 

The  Parotid  Duct  lies  one  finger's  breadth  below  the  zygo- 
matic arch,  and,  when  the  teeth  are  clenched,  it  may  be  rolled 
up  and  down  against  the  tense  masseter.  It  emerges  from  the 
forepart  of  the  gland,  and  runs  forwards  on  the  masseter  to  its 
anterior  border.  It  then  passes  medially,  piercing  the  buccin- 
ator to  reach  the  mucous  membrane  of  the  cheek.  Opposite 
the  second  upper  molar  tooth  the  parotid  duct  opens  into  the 
mouth.  Septic  infection  may  travel  backwards  from  the  mouth 
along  the  duct  and  involve  the  gland  itself. 

Calculi  lodged  in  the  distal  portion  of  the  duct  may  be 
removed  by  slitting  up  the  duct  from  its  opening  within  the 
mouth.  A  similar  route  is  adopted  for  opening  abscesses  in 
connection  with  the  buccinator  lymph  glands.  The  incision  is 
made  horizontally  through  the  mucous  membrane  to  one  side 
of  the  opening  of  the  parotid  duct,  and  both  the  mucous  mem- 
brane and  the  buccinator  are  cut  parallel  to  the  course  of  the 
duct. 

The  Buccinator  arises  from  the  outer  alveolar  margins  of 
the  maxilla  and  mandible  in  the  region  of  the  molar  teeth,  and 
its  posterior  border  is  attached  to  the  pterygo-mandibular 
raphe,  which  is  a  fibrous  band  extending  from  the  hamulus  of 
the  medial  pterygoid  lamina  (plate)  to  the  posterior  end  of  the 
mylo-hyoid  line  of  the  mandible.  Its  fibres  run  horizontally 
forwards,  and  fuse  with  the  orbicularis  oris  at  the  angle  of  the 
mouth.  Like  the  muscles  of  facial  expression,  it  is  supplied  by 
the  facial  nerve.  It  forms  the  muscular  stratum  of  the  cheek, 
and  when  it  is  paralysed  portions  of  food  become  retained 
between  the  cheek  and  the  gums  on  the  affected  side. 

The  lymph  glands  of  the  parotid  region  are  divisible  into 
two  groups;  one, the  anterior  auricular  (pre-auricular) ,  lies  super- 
ficial to  the  sheath,  while  the  other,  the  group  of  parotid  lymph 


THE  FACE,  MOUTH  AND  PHARYNX  177 

glands,  is  scattered  throughout  the  substance  of  the  gland, 
though  chiefly  situated  near  its  surface.  The  anterior  auricular 
lymph  glands  drain  the  frontal  and  temporal  regions  and  receive 
some  of  the  deep  facial  lymph  vessels.  The  parotid  lymph 
glands  drain  the  upper  and  posterior  part  of  the  naso-pharynx 
and  the  pterygoid  lymph  glands.  Abscesses  arising  in  connec- 
tion with  the  anterior  auricular  lymph  glands  point  superficially, 
but,  when  they  arise  in  connection  with  the  parotid  lymph  glands, 
they  rarely  point  on  the  surface,  owing  to  the  strength  of  the 
parotid  sheath.  In  these  cases  the  pus  may  pass  upwards  and 
find  its  way  into  the  external  acoustic  meatus,  or  it  may  travel 
medially  and  reach  the  side  wall  of  the  nasal  pharynx.  In  the 
latter  case  it  ultimately  descends  along  the  medial  side  of  the 
carotid  sheath. 

Pus  inside  the  parotid  gland  is  evacuated  by  Hilton's  method, 
but  the  surgeon  must  be  certain  of  its  presence  before  exploring 
the  gland.  Irreparable  damage  may  be  done  to  the  facial 
nerve  by  repeated  unsuccessful  endeavours  to  locate  pus. 

An  isolated  lymph  gland  of  the  parotid  group,  which  lies 
near  the  surface  of  the  salivary  gland  at  about  the  level  of  the 
tragus,  is  not  uncommonly  affected  alone.  It  can  be  shelled 
out  through  a  small  horizontal  incision,  parallel  to  the  facial 
nerve.  The  superficial  structures,  the  sheath  of  the  gland,  and 
probably  some  parotid  tissue  are  cut  through  before  it  is  reached. 
Mixed  tumours  of  the  parotid  (as  well  as  some  inflammatory 
swellings)  sometimes  produce  slight  facial  paralysis.  Encapsuled 
tumours  can  often  be  enucleated  through  a  larger  incision  in 
the  same  region  without  much  damage  to  the  facial  nerve, 
provided  that  all  cutting  is  done  parallel  to  its  branches  (p.  178). 

When  Eemoval  of  the  whole  Parotid  Gland  for  malignant 
disease  is  contemplated,  a  large  curved  incision  is  necessary. 
It  commences  at  the  mastoid  process,  and  passes  down  the 
anterior  border  of  the  sterno-mastoid  to  a  point  below  the  angle 
of  the  mandible,  and  it  is  then  carried  upwards  and  forwards 
on  to  the  face.  The  flap  is  turned  upwards,  and  the  external 
jugular  vein  and  the  external  carotid  artery  are  secured  at  once. 
The  gland  is  most  easily  freed  from  below  and  then  from  in  front, 
after  ligature  of  the  parotid  duct.  In  separating  the  deep 
surface  of  the  gland  from  the  muscles  attached  to  the  styloid 
process,  care  must  be  taken  lest  the  internal  jugular  vein  be 
injured,  as  it  may  be  in  direct  contact  with  the  gland. 

The  Facial  Nerve  (pp.  213,  215)  leaves  the  skull  at  the 

12 


178  THE  HEAD  AND  NECK 

stylo-mastoid  foramen  and  turns  forwards,  laterally  and  slightly 
downwards.  It  at  once  enters  the  deep  surface  of  the  parotid 
gland  and  gradually  becomes  more  superficial.  At  the  level 
of  the  lobule  of  the  ear,  one  finger's  breadth  below  the  zygomatic 
arch,  the  facial  nerve  may  be  rolled  against  the  neck  of  the 
mandible,  although  it  is  here  embedded  in  the  parotid  gland. 

Temporary  facial  paralysis  may  result  from  bruising  of  the 
nerve  by  the  application  of  forceps  at  birth,  as  the  stylo-mastoid 
foramen  in  the  infant  is  placed  on  the  infero-lateral  aspect  of 
the  skull  and  the  mastoid  process  is  not  yet  developed  (p.  210). 

Immediately  after  it  leaves  the  skull  the  facial  nerve  gives 
off  its  posterior  auricular  and  digastric  branches ;  the  latter 
supplies  the  stylo-hyoid  in  addition  to  the  posterior  belly  of  the 
digastric.  Within  the  parotid  gland  the  nerve  at  once  breaks 
up  into  its  main  branches,  which  radiate  away  from  one  another 
as  they  leave  the  gland  (Fig.  52).  They  all  terminate  by  sup- 
plying muscles  of  facial  expression. 

Incisions  ascending  from  the  neck  behind  the  angle  of  the 
mandible  must  be  only  skin-deep  at  the  level  of  the  lobule,  other- 
wise the  main  trunk  of  the  facial  nerve  may  be  divided. 
Similarly,  incisions  on  the  face  should  be  made  parallel  to  its 
branches  of  distribution ;  they  should  therefore  radiate  from 
the  middle  of  the  anterior  border  of  the  lobule.  In  the  child, 
up  to  the  age  of  two,  the  nerve  may  be  divided  by  incisions 
beneath  the  auricle,  such  as  that  employed  in  mastoiditis  (p.  2 15). 

Division  of  the  cervical  branch  of  the  facial  nerve  is  referred 
to  on  p.  108, 

Facio-Hypoglossal  Anastomosis  is  performed  for  facial 
paralysis  produced  by  disease  or  injury  of  the  nerve  in  its  course 
through  the  facial  canal  (aqueduct  of  Fallopius). 

The  incision,  which  begins  high  up  on  the  mastoid  process 
and  runs  downwards  to  the  greater  cornu  of  the  hyoid  bone,  is 
planned  so  as  to  give  good  exposure  of  both  nerves. 

The  deep  fascia  is  incised  immediately  in  front  of  the  mastoid 
process  and  the  parotid  gland  is  pushed  forwards.  An  aneurism 
needle  is  inserted  deeply  in  the  gap  thus  made,  and  hooked  up 
towards  the  surface.  The  facial  nerve,  which  is  caught  by  the 
needle  on  a  level  with  the  middle  point  of  the  lobule  of  the  ear, 
is  traced  to  the  stylo-mastoid  foramen  and  there  divided.  In 
order  to  get  a  sufficiently  long  segment  of  the  nerve  the  bone 
may  require  to  be  chipped  away,  and  the  nerve  may  be  traced 
for  a  short  distance  into  the  parotid  gland. 


THE  FACE,  MOUTH  AND  PHARYNX 


179 


The  hypoglossal  nerve  is  found  in  the  anterior  end  of  the 
wound  as  it  lies  in  the  angular  interval  between  the  two  bellies 
of  the  digastric  (p.  145).  The  incision  is  carried  down  through 
the  deep  fascia  till  the  posterior  belly  of  the  digastric  and  the 
submaxillary  gland  are  exposed.  This  part  of  the  hypoglossal 
nerve  is  chosen  by  the  surgeon  because  a  long  segment  is  required 
to  minimise  any  strain  on  the  subsequent  anastomosis.  Further, 
the  nerve  is  easily  found  in  this  part  of  its  course,  whereas,  at  a 
higher  level,  it  lies  more  deeply,  and  its  isolation  would  involve 
considerable  risk  of  injury  to  the  internal  jugular  vein.  The 
nerve  is  cut  through  and  withdrawn  from  under  cover  of  the 
posterior  belly  of  the  digastric.  This  necessitates  section  of  the 


Upper  joint  cavity 
Discus  articularis       \ 
Lower  joint  cavity    \ 
Capsule          \ 


Tuberculum  articulare 


Mastoid  process 

Styloid  process 


FIG.  53. — Section  through  the  Mandibular  Joint. 

branch  of  supply  to  the  thyreo-hyoid  and,  perhaps,  of  the  ramus 
descendens  hypoglossi.  The  proximal  extremity  of  the  hypo- 
glossal  nerve  is  then  turned  up  over  the  posterior  belly  of  the 
digastric  and  united  to  the  distal  portion  of  the  facial  nerve, 
which  is  turned  down  to  meet  it. 

In  similar  cases  the  (spinal)  accessory  nerve  may  be  united 
to  the  facial.  It  is  found  .at  the  anterior  border  of  the  sterno- 
mastoid  (p.  135). 

Temporo-Mandibular  Joint. — At  this  joint  the  condyle  of 
the  mandible  articulates  with  the  mandibular  (glenoid)  fossa 
of  the  temporal  bone,  which  is  limited  posteriorly  by  the  tym- 
panic plate  and  in  front  by  the  articular  tubercle  (eminentia 
articularis).  The  capsule,  which  is  loose  and  so  permits  of  free 
movement,  is  attached  to  the  margins  of  the  cartilage-covered 


i8o  THE  HEAD  AND  NECK 

areas.  It  gives  attachment  on  its  inner  surface  to  the  discus 
articularis,  which  divides  the  joint  cavity  into  an  upper  and  a 
lower  part.  Anteriorly,  the  capsule  is  deficient,  and  the  tendon 
of  the  external  pterygoid  gains  insertion  into  the  articular  disc. 

Laterally,  the  capsule  is  strengthened  by  the  temper o- 
mandibular  (external  lateral)  ligament,  the  fibres  of  which  are 
directed  downwards  and  backwards  to  the  lower  part  of  the  neck 
of  the  condyle.  The  obliquity  of  these  fibres  helps  to  prevent 
the  condyle  from  passing  backwards  and  fracturing  the  tym- 
panic plate,  when  a  blow  falls  upon  the  chin. 

In  the  movements  of  protrusion  and  retraction  of  the  man- 
dible, the  condyle  and  the  articular  disc  move  together  over  the 
surface  of  the  mandibular  fossa.  When  the  mouth  is  opened 
the  articular  disc  and  the  condyle  both  move  forwards,  but,  at 
the  same  time,  the  condyle  rotates  around  a  transverse  axis, 
which  passes  through  the  lower  attachment  of  the  temporo- 
mandibular  (external  lateral)  ligament.  The  latter  becomes 
tense  when  the  mouth  is  widely  opened  and  the  condyle  rests 
on  the  summit  of  the  articular  tubercle  (eminentia  articularis). 
In  this  position  the  mandible  can  easily  be  dislocated  either  by 
a  blow  on  the  chin  or  even  by  the  forcible  contraction  of  the 
external  pterygoids.  The  method  adopted  to  reduce  this  dis- 
location first  depresses  the  condyle  so  as  to  disengage  it  from 
the  front  of  the  articular  tubercle,  and  then,  by  partial  closure 
of  the  mouth,  the  condyle  is  made  to  pass  back  into  the  man- 
dibular fossa.  Considerable  force  is  sometimes  required  to 
overcome  the  spasm  of  the  muscles  of  mastication. 

The  spheno-mandibular  (internal  lateral)  ligament  is  placed 
at  some  distance  from  the  joint  and  gives  it  no  support.  At- 
tached above  to  the  spine  of  the  sphenoid,  the  ligament  descends 
to  gain  attachment  to  the  margin  of  the  mandibular  foramen. 
The  internal  maxillary  artery  and  the  inferior  alveolar  (dental) 
vessels  and  nerve  intervene  between  the  ligament  and  the  ramus 
of  the  mandible. 

At  the  symphysis  the  mandibLe  is  strengthened  by  the 
mental  protuberance,  and,  when  fractured,  it  usually  gives  way 
at  the  margin  of  this  elevation.  The  fracture  passes  through 
the  large  canine  socket  and  is  usually  compound,  as  the  mucous 
membrane  of  the  mouth  is  so  firmly  attached  to  the  bone  that 
it  is  almost  always  torn.  The  inferior  alveolar  (dental)  nerve 
may  be  implicated  in  the  callus  and  cause  neuralgic  pain,  which 
niay  be  referred  over  the  distribution  of  the  buccinator  and 


THE  FACE,  MOUTH  AND  PHARYNX  181 

auriculo-temporal  nerves.  If  the  nerve  is  completely  paralysed, 
the  area  supplied  by  its  mental  branch  loses  its  sensibility, 
and  when  drinking,  the  patient  can  only  appreciate  the  glass 
with  his  lips  on  the  uninjured  side. 

The  Temporal  Muscle  arises  from  the  temporal  fossa  and  descends  under 
cover  of  the  zygomatic  arch,  to  be  inserted  into  the  margins  and  deep  surface 
of  the  coronoid  process.  The  Masseter  arises  from  the  zygomatic  arch,  and 
is  inserted  into  the  lateral  surface  of  the  mandibular  ramus.  Both  muscles 
are  powerful  elevators  of  the  mandible,  and  are  supplied  by  the  mandibular 
division  of  the  trigeminal  nerve. 

The  External  Pterygoid  arises  from  the  skull  in  the  region  of  the  pterygoid 
process  (plates)  of  the  sphenoid,  and  passes  almost  horizontally  backwards, 
to  be  inserted  into  the  condyle  and  the  articular  disc  (p.  180).  Its  action  is 
to  draw  the  condyle  and  the  articular  disc  forwards,  thus  protruding  the 
mandible.  As  it  passes  backwards  it  is  in  contact  with  the  deep  surface  of 
the  temporal  muscle.  The  Internal  Plerygoid  has  a  similar  but  deeper  origin. 
Its  fibres  run  downwards  and  laterally,  as  well  as  backwards,  to  reach  the 
internal  surface  of  the  angle  of  the  mandible.  Both  pterygoid  muscles  are 
supplied  by  the  mandibular  division  of  the  trigeminal.  When  the  two  ptery- 
goid muscles  of  one  side  act  alone,  the  mandible  is  twisted  over  to  the  opposite 
side.  This  action  is  seen  in  lateral  chewing  movements,  and  in  paralysis  of 
the  mandibular  nerve  the  mandible  is  permanently  pulled  over  to  the  same 
side  as  the  lesion. 

The  Internal  Maxillary  Artery  arises  from  the  external 
carotid  in  the  parotid  gland  at  the  level  of  the  neck  of  the 
mandible.  It  passes  forwards  deep  to  the  bone  but  superficial 
to  the  spheno-mandibular  ligament.  It  may  run  either  super- 
ficial or  deep  to  the  external  pterygoid,  and  it  terminates  in  the 
pterygo-palatine  (spheno-maxillary)  fossa,  where  it  gives  off 
the  palatine,  infra-orbital,  and  numerous  other  small  branches. 
In  the  earlier  part  of  its  course  the  artery  gives  off  (i)  the  middle 
meningeal,  which  ascends  deep  to  the  external  pterygoid,  to 
enter  the  skull  through  the  foramen  spinosum  ;  (2)  the  inferior 
alveolar  (dental),  which  enters  the  mandibular  foramen  ;  and  (3) 
branches  to  the  surrounding  muscles.  The  corresponding  veins 
form  a  plexus  round  the  pterygoid  muscles,  which  communicates 
with  the  cavernous  sinus  (p.  225)  above,  the  anterior  facial 
vein  in  front,  and  the  posterior  facial  vein  (temporo-maxillary) 
behind. 

Operations  on  the  Mandible.— The  periosteum  of  the 
mandible  is  thick  and  strong,  and  can  be  easily  stripped  off  the 
bone.  Further,  it  is  able  to  reform  large  portions  of  the  bone 
after  subperiosteal  resection,  an  operation  which  is  employed 
with  advantage  in  tuberculous  and  chronic  septic  disease  of  the 
body  and  ramus.  A  curved  incision  is  made  along  the  posterior 
third  of  the  inferior  border  of  the  body,  round  the  angle,  and 


182  THE  HEAD  AND  NECK 

up  the  posterior  border  of  the  ramus.  The  incision,  which 
must  not  be  carried  upwards  too  far  lest  the  facial  nerve  be 
injured  (p.  178),  penetrates  down  to  the  bone,  and  the  periosteum 
may  be  stripped  off  along  with  the  masseter  laterally  and  the 
internal  pterygoid  medially,  so  as  to  leave  the  tuberculous  bone 
exposed.  The  affected  area  may  then  be  removed  without 
opening  into  the  mouth. 

In  Excision  of  the  Mandible  for  malignant  disease  the  bone  is 
removed  along  with  its  periosteal  covering.  The  incision  begins 
at  the  margin  of  the  lower  lip  and  is  carried  down  in  the  middle 
line  to  the  lower  border  of  the  bone,  along  which  it  is  carried 
backwards  to  the  angle.  In  this  part  of  the  incision,  the  external 
maxillary  artery  and  its  accompanying  vein  are  cut  through 
and  secured.  The  incision  is  then  carried  upwards  along  the 
posterior  border  of  the  ramus  to  the  level  of  the  tragus.  It  is 
only  skin-deep  above,  so  that  the  facial  nerve  is  not  injured. 
The  soft  parts  are  reflected  from  the  lateral  aspect  of  the  bone 
and  the  masseter  is  cut  away  from  its  insertion,  and  the  mucous 
membrane  is  divided  as  it  is  reflected  from  the  cheek  on  to  the 
external  aspect  of  the  gum.  A  Gigli  saw  is  passed  upwards, 
internal  to  the  bone,  through  an  opening  made  in  the  mylo- 
hyoid  a  little  to  one  side  of  the  median  plane,  and  it  is  brought 
out  into  the  mouth  through  the  mucous  membrane  of  its  floor. 
The  mandible  is  then  divided  through  the  socket  of  the  lateral 
incisor  tooth,  and  in  this  way  the  mental  spine  (genial  elevation), 
with  its  muscular  attachments,  is  left  intact.  The  bone  is 
next  depressed  and  dragged  outwards  through  the  wound,  and 
the  origin  of  the  mylo-hyoid  and  the  mucous  membrane  on  the 
inner  aspect  of  the  gum  are  cut  through,  until  the  internal  ptery- 
goid is  reached.  When  the  muscle  and  the  spheno-mandibular 
(internal  lateral)  ligament,  which  lies  on  its  surface,  have  been 
divided,  the  inferior  alveolar  artery  and  nerve  are  exposed 
between  them  and  the  ramus.  After  they  have  been  secured, 
the  bone  may  be  depressed  still  further  so  as  to  bring  the  coronoid 
process  into  view.  It  may  be  cut  across,  01  the  temporal  muscle 
may  be  detached  from  its  insertion.  The  mandible  is  now  only 
held  in  position  by  the  external  pterygoid  and  the  temporo- 
mandibular  joint. 

If  these  structures  are  cut  through  with  the  knife,  the  internal 
maxillary  artery  (p.  181)  is  in  great  danger,  and  it  is  safer  to 
twist  the  condyle  away  from  its  attachments. 

The  Mandibular  (Inferior  Maxillary)  Nerve  is  a 


THE  FACE,  MOUTH  AND  PHARYNX  183 

branch  of  the  trigeminal,  and  leaves  the  skull  through  the 
foramen  ovale.  It  at  once  breaks  up  into  numerous  branches, 
which  at  first  lie  deep  to  the  external  pterygoid  and  on 
the  lateral  wall  of  the  nasal  pharynx. 

The  nerve  may  be  reached,  for  the  purposes  of  injection,  by 
inserting  a  needle  immediately  below  the  zygomatic  arch  at  a 
point  2-5  cm.  in  front  of  the  external  acoustic  meatus.  It  is 
directed  medially  and  slightly  backwards  to  a  depth  of  4  cm., 
when  the  point  comes  into  contact  with  the  nerve  (Symington). 
Before  reaching  the  nerve,  the  needle  pierces  the  masseter 
muscle  and  passes  through  the  mandibular  (sigmoid)  notch, 
the  temporal  and  external  pterygoid  muscles.  If  the  needle 
is  passed  in  for  more  than  4  cm.  it  pierces  the  lateral  wall  of  the 
nasal  pharynx. 

Branches. — (i)  The  Auricula-temporal  nerve  passes  back- 
wards into  the  parotid  gland  (pp.  174,  211).  (2)  The  Buccinator 
(long  buccal)  pierces  the  external  pterygoid,  and  frequently  the 
anterior  fibres  of  the  temporal,  before  it  appears  in  the  face  (p. 
174).  (3)  The  Inferior  Alveolar  (Dental)  nerve  runs  downwards, 
deep  to  the  external  but  superficial  to  the  internal  pterygoid, 
and  enters  the  mandibular  foramen  in  company  with  the  artery 
of  the  same  name.  As  it  enters  the  foramen  it  gives  off  (4)  the 
Mylo-hyoid  nerve  (p.  144).  (5)  The  Lingual  nerve  lies  just  anterior 
to  the  inferior  alveolar.  On  the  inner  surface  of  the  body  of 
the  mandible  it  lies  above  the  mylo-hyoid  line  and,  opposite  the 
third  molar  (p.  184)  tooth  it  is  only  covered  by  the  mucous 
membrane  of  the  mouth.  (6)  The  remaining  branches  of  the 
mandibular  nerve  are  all  motor  and  supply  the  muscles  of 
mastication,  viz.  the  temporal,  the  masseter,  and  the  external 
and  internal  pterygoids.  Paralysis  of  this  nerve  is  referred  to 
on  p.  181. 

The  inferior  alveolar  and  lingual  nerves  are  sometimes 
involved  in  severe  neuralgia,  which  affects  the  lower  teeth  and 
gums  and  the  tongue.  They  may  be  approached  (i)  through 
the  skin  of  the  cheek,  or  (2)  from  the  inside  of  the  mouth. 

i.  A  curved  incision  is  carried  down  the  lower  part  of  the 
posterior  border  of  the  ramus  and  forwards  along  the  inferior 
border  of  the  mandible.  This  incision  passes  down  to  the  bone 
at  once,  and  a  flap,  consisting  of  all  the  superficial  structures, 
including  the  periosteum,  is  thrown  forwards.  The  ramus  is 
then  trephined  slightly  above  the  last  molar  tooth,  and  the 
piece  of  bone  is  removed,  exposing  the  periosteum  on  its  deep 


184  THE  HEAD  AND  NECK 

surface.  This  is  cut  away,  and  the  two  nerves  are  found  lying 
on  the  internal  pterygoid  muscle. 

2.  The  mucous  membrane  of  the  mouth  may  be  divided 
upwards  and  backwards  from  the  level  of  the  last  molar  tooth  of 
the  mandible  along  the  inner  surface  of  the  ramus.  The  lingual 
nerve  is  found  lying  in  the  submucous  tissue,  and  may  be  traced 
backwards  between  the  ramus  and  the  internal  pterygoid  muscle 
until  the  lingula  of  the  mandibular  foramen  can  be  felt.  The 
inferior  alveolar  nerve  and  vessels  are  found  as  they  enter  the 
mandibular  foramen  a  little  posterior  to  the  lingual  nerve. 

This  operation  is  carried  out  when  the  patient  is  anxious  to 
avoid  a  skin  incision  and  the  subsequent  scar. 

Dentition. — The  first  of  the  deciduous  teeth  to  appear  are  the  lower 
central  incisors,  and  they  are  usually  cut  between  the  sixth  and  eighth  months. 
The  lateral  incisors  soon  follow,  and  by  the  end  of  the  year  the  first  deciduous 
molars  should  be  visible.  Early  in  the  second  year  the  canine  teeth  erupt, 
and  the  temporary  set  is  completed  by  the  appearance  of  the  second  deciduous 
molar  about  the  commencement  of  the  third  year.  The  lower  teeth  usually 
appear  somewhat  in  advance  of  the  upper. 

The  first  lower  molars  are  the  first  of  the  permanent  teeth  to  erupt,  and 
should  be  present  by  the  end  of  the  seventh  year.  They  are  followed  during 
the  next  two  years  by  the  central  and  lateral  incisors.  Within  the  next  four 
years  the  first  and  second  premolars,  the  canines,  and  the  second  molars 
appear  in  that  order,  but  the  eruption  of  the  last-named  is  often  delayed  till 
the  fifteenth  or  sixteenth  year.  The  permanent  set  is  completed  by  the  erup- 
tion of  the  third  molars,  which  may  appear  at  any  time  between  eighteen 
and  thirty. 

Irregular  dentition  is  common  in  rickets,  and  the  upper  permanent  in- 
cisors are  sometimes  notched.  The  notching  corresponds  to  a  small  segment 
of  a  large  circle,  and  has  to  be  distinguished  from  the  notching  of  the  same 
teeth  in  congenital  syphilis  (Hutchinson*  s  Teeth),  which  corresponds  to  a  large 
segment  of  a  small  circle. 

The  developing  tooth  is  enclosed  in  a  membranous  sac,  which,  under 
normal  conditions,  atrophies  as  the  tooth  increases  in  size.  Occasionally, 
however,  the  sac  fails  to  atrophy,  and  develops  into  a  dentigerous  cyst,  which 
expands  the  bone.  The  cyst  usually  projects  more  to  the  lateral  than  to 
the  medial  side,  and  contains  the  undeveloped  tooth  attached  to  its  wall. 

Alveolar  Abscess. — The  roots  of  the  teeth  are  firmly  fixed 
in  their  sockets  by  a  highly  vascular  fibrous  membrane,  the 
alveola -dental  periosteum.  In  peri-odontitis  this  membrane 
swells  up  and  becomes  very  sensitive.  It  tends  to  extrude  the 
tooth  slightly  from  its  socket,  so  that  biting  is  rendered  a  painful 
process.  When  an  alveolar  abscess  forms,  the  pus  may  make 
its  way  out  around  the  neck  of  the  tooth  or  burrow  through  the 
alveolus,  giving  rise  to  a  "  gumboil."  In  the  maxilla  it  may 
penetrate  the  bone  laterally  and  appear  near  the  reflection  of 
the  mucous  membrane  from  the  gum  to  the  cheek,  or  it  may 


THE  FACE,  MOUTH  AND  PHARYNX 


pass  medially,  stripping  up  the  muco-periosteum,  and  form  an 
abscess  on  the  palate  (Fig.  54).  Alveolar  abscess  in  connection 
with  the  teeth  of  the  mandible  has  been  described  on  p.  145. 

The  Tongue  is  subdivided  into  a  pharyngeal  and  an  oral 
portion  by  the  sulcus  terminalis,  a  V-shaped  groove  situated  at 


Maxilla  _ 
Tooth  abscess  -- 
Muco-periosteum  of  palate  — 
Tone ue    - 


Periosteum 
Tooth  abscess 


Maxillary  sinus 
Inferior  meatus 

Alveolar  abscess 
Maxilla 

Mucous  mem- 
brane of  cheek 


•Submaxilkry  duct 

'Lingual  nerve 
Genio-glossus 
Sublingual  gland 

Genio-hyoid 


Skin 


Digastric,  ant.  belly      j 7 

Lymph  gland        / 


Deep  cervical  fascia 


Abcess 


Mylo-hyoid 
Hyoid  bone 


FIG.  54. — Frontal  Section  through  the  Mouth.  Four  varieties  of  alveolar 
abscess  are  shown.  In  the  maxilla,  on  the  right  side,  the  pus  has  spread 
laterally,  forming  an  abscess  under  the  mucous  membrane  ;  on  the  left 
side,  it  has  spread  medially,  forming  a  palatal  abscess.  In  the  mandible, 
on  the  right  side,  the  pus  has  perforated  the  bone  medial  to  the  attach- 
ment of  the  deep  cervical  fascia,  forming  an  abscess  which  is  covered  by 
the  fascia  and  the  skin  ;  on  the  left  side,  the  pus  has  perforated  the  bone 
outside  the  deep  fascia,  forming  an  abscess  immediately  under  the  skin. 

the  junction  of  its  middle  and  posterior  thirds.  The  apex  of 
the  V  lies  posteriorly  and  coincides  with  the  foramen  caecum 
(p.  169).  Numerous  collections  of  lymphoid  tissue  are  present 
in  the  pharyngeal  portion  of  the  tongue  (Lingual  tonsils}.  They 
form  small  rounded  elevations,  and  each  possesses  a  crypt  into 
which  mucous  glands  open. 

The  mucous  membrane  on  the  upper  surface  of  the  anterior 
two-thirds  of  the  tongue  is  roughened  by  the  projection  of 
numerous  papillae,  but  on  the  under  surface  it  is  smooth,  and 


186  THE  HEAD  AND  NECK 

the  profunda  veins  (ranine)  can  be  seen  shining  through  it. 
Near  the  tip  of  the  tongue,  and  embedded  in  the  muscles  on  its 
under  surface,  there  is  a  collection  of  mucous  and  serous  glands, 
which  occasionally  give  rise  to  small  cysts.  The  under  surface 
of  the  tongue  is  attached  to  the  floor  of  the  mouth  by  a  fold  of 
mucous  membrane,  termed  thefrenulum,  which  may  sometimes 
be  so  short  as  to  interfere  with  the  free  movement  of  the  organ 
("  tongue  tie  "). 

The  submaxillary  (Wharton's)  duct  opens  on  a  small  papilla, 
which  is  placed  lateral  to  the  point  where  the  frenulum  of  the 
tongue  joins  the  mucous  membrane  of  the  floor  of  the  mouth. 
The  plica  sublingualis,  which  overlies  the  sublingual  gland  and 
is  pierced  by  its  ducts,  runs  backwards  and  laterally  from  the 
papilla. 

The  tongue  is  plentifully  supplied  with  lymph  vessels,  from 
which  arise  the  large  collecting  trunks,  viz.  (i)  apical,  (2)  mar- 
ginal, (3)  basal,  (4)  central. 

(i)  The  Apical  Lymph  Vessels  drain  the  tip  of  the  tongue 
and  open  into  the  submental  lymph  glands.  Some,  however, 
pass  directly  to  join  the  lower  anterior  group  of  the  deep  cervical 
lymph  glands  at  the  level  of  the  sixth  cervical  vertebra,  and  in 
consequence  these  glands  may  be  involved  at  a  very  early  stage 
in  malignant  disease  of  the  tongue.  (2)  The  Marginal  Lymph 
Vessels  drain  the  lateral  borders  of  the  tongue.  Some  of  them 
join  the  submaxillary  lymph  glands,  but  the  remainder  run 
backwards  and  downwards  to  open  into  the  deep  cervical  lymph 
glands,  which  lie  on  the  carotid  sheath  opposite  the  third,  fourth, 
and  fifth  cervical  vertebrae.  (3)  The  Basal  Lymph  Vessels 
drain  the  dorsum  of  the  tongue.  After  running  backwards 
towards  the  lower  pole  of  the  palatine  tonsil,  they  pierce  the 
superior  constrictor,  and  open  into  the  upper  anterior  group  of 
the  deep  cervical  lymph  glands  under  cover  of  the  posterior 
belly  of  the  digastric.  They  communicate  very  freely  with  the 
corresponding  vessels  of  the  opposite  side,  a  point  of  great 
importance  clinically.  (4)  The  Central  Lymph  Vessels  drain 
the  substance  of  the  tongue  and  descend  between  the  genio- 
glossi,  to  terminate  in  the  lower  anterior  group  of  the  deep 
cervical  lymph  glands. 

Recurrence  of  malignant  disease  of  the  tongue  usually  mani- 
fests itself  in  the  lymph  glands  and  not  in  the  mouth.  In 
excision  of  the  tongue  for  malignant  disease  it  is  of  the  greatest 
importance  to  remove  all  the  lymph  glands  which  drain  the  area 


THE  FACE,  MOUTH  AND  PHARYNX  187 

involved,  i.e.  not  only  the  proximal  glands  but  also  the  whole 
chain  of  the  deep  cervical  lymph  glands. 

On  this  account  Butlin  advocated  the  complete  dissection  of 
the  anterior  triangle  as  a  routine  measure.  The  area  is  exposed 
by  two  incisions,  one  along  the  whole  length  of  the  anterior 
border  of  the  sterno-mastoid  and  the  other  extending  from  the 
symphysis  menti  to  meet  the  first  at  the  level  of  the  upper 
border  of  the  thyreoid  cartilage.  The  two  skin  flaps  are  retracted 
and  the  exposed  platysma  is  removed,  since  it  is  traversed  by 
lymph  vessels  which  connect  the  deep  and  superficial  cervical 
lymph  glands.  For  the  same  reason  the  investing  layer  of  the 
deep  fascia  and  the  pretracheal  fascia  are  both  removed,  as  well 
as  the  stylo-mandibular  ligament.  All  the  anterior  deep  cervical 
lymph  glands  are  taken  away,  and  the  lower  part  of  the  parotid 
salivary  gland  is  removed  in  order  to  give  access  to  the  uppermost 
members  of  the  group.  In  order  to  make  certain  that  none  of 
the  submaxillary  lymph  glands  are  overlooked,  the  submaxillary 
salivary  gland  is  also  excised.  Finally,  after  the  removal  of  the 
submental  lymph  glands,  the  median  raphe  of  the  mylo-hyoids 
is  cut  through,  and  a  search  is  made  between  the  two  genio-hyoid 
muscles. 

When  this  operation  is  carried  out  as  a  preliminary  step  to 
removal  of  the  tongue,  and  where  there  is  extensive  glandular 
infection,  the  external  carotid  artery  and  internal  jugular  vein 
may  be  resected. 

On  account  of  its  rich  network  of  lymphatics,  and  the  presence 
in  its  substance  of  a  quantity  of  loose  connective  tissue,  the 
tongue  may,  in  acute  glossitis,  suddenly  become  so  enormously 
swollen  as  to  fill  up  the  mouth  and  protrude  from  it.  Relief 
may  be  obtained  by  free  incisions,  which  are  made  parallel  to 
the  course  of  the  profunda  linguae  (ranine)  artery  (i.e.  from 
behind  forwards).  In  the  event  of  injury  to  the  vessel,  which 
lies  on  a  deep  plane,  the  haemorrhage  may  be  controlled  by 
introducing  the  finger  into  the  mouth  and  hooking  the  base  of 
the  tongue  forwards  against  the  mandible. 

The  position  of  lingual  dermoids  is  described  on  p.  152. 

Removal  of  One  Half  of  the  Tongue  for  malignant  disease 
may  be  performed  entirely  through  the  mouth.  The  mucous 
membrane  is  cut  through  from  the  frenulum  linguae  to  the 
glosso-palatine  arch  (anterior  pillar  of  the  fauces),  along  the 
line  of  its  reflection  from  the  gum.  A  second  incision  is  made, 
commencing  at  the  frenulum,  passing  over  the  under  surface  of 


i88  THE  HEAD  AND  NECK 

the  tongue,  and  backwards  on  the  dorsum  in  the  median  plane 
for  some  distance  beyond  the  disease.  The  tongue  is  next  drawn 
forwards  from  the  mouth  and  split  in  the  median  plane.  The 
two  incisions  in  the  mucous  membrane  are  united  by  a  transverse 
cut,  and  the  stylo-glossus  is  exposed  and  divided  as  it  enters 
the  postero-lateral  aspect  of  the  tongue.  The  genio-glossus  and 
the  hyo-glossus  are  cut  away  from  their  attachments  to  the 
hyoid  bone,  and  at  this  stage  the  lingual  artery  (p.  154)  is  secured. 
In  the  removal  of  the  whole  tongue  by  the  oral  route,  it  is 
advantageous  to  split  the  organ  and  take  it  away  in  two  pieces. 

The  Palatine  (Faucial)  Tonsil  lies  in  the  lower  part  of 
a  triangular  depression,  the  tonsillar  sinus,  on  the  lateral  wall 
of  the  pharynx.  The  sinus  is  bounded  in  front  and  behind  by 
the  palatine  arches  (pillars  of  the  fauces),  which  meet  above 
on.  the  posterior  border  of  the  soft  palate.  The  supra-tonsillar 
fossa  is  a  small  depression  which  is  situated  above  the  tonsil  in 
the  upper  part  of  the  tonsillar  sinus.  Peri-tonsillar  abscess 
gives  rise  to  a  swelling,  which  may  involve  the  adjoining  part  of 
the  palate  as  well  as  the  supra-tonsillar  fossa.  It  should  be 
incised  with  a  guarded  knife,  and  the  pus  evacuated  by  Hilton's 
method.  The  incision  is  made  at  the  point  where  the  horizontal 
line  corresponding  to  the  free  border  of  the  soft  palate  meets 
the  vertical  line  corresponding  to  the  glosso- palatine  arch 
(anterior  pillar  of  the  fauces). 

Development. — The  palatine  tonsil  does  not  begin  to  develop 
till  the  fourth  month  of  foetal  life,  although  the  tonsillar 
sinus,  which  represents  a  persistent  part  of  the  second  visceral 
pouch,  appears  at  a  much  earlier  date.  Epithelial  buds,  which 
subsequently  become  the  tonsillar  crypts,  grow  out  from  the 
mucous  membrane  on  the  lateral  pharyngeal  wall  into  the  sur- 
rounding mesoderm.  The  latter  becomes  converted  into 
lymphoid  tissue  which  forms  the  greater  part  of  the  tonsil. 
Its  growth  in  a  lateral  direction  is  obstructed  by  the  pharyngeal 
aponeurosis,  and  so,  as  the  organ  grows,  it  bulges  into  the  oral 
part  of  the  pharynx.  The  tonsil,  therefore,  consists  partly  of 
mucous  membrane,  which  covers  its  medial  surface  and  lines  its 
crypts,  and  partly  of  lymphoid  tissue. 

The  deep  surface  of  the  tonsil  has  no  definite  capsule,  and 
is  only  separated  from  the  pharyngeal  aponeurosis,  which  lines 
the  superior  constrictor,  by  loosely  arranged  areolar  tissue. 
On  this  account  the  tonsil  can  readily  be  dragged  medially  from 
its  fossa  in  the  operation  of  enucleation.  Hypertrophy  of  the 


THE  FACE,  MOUTH  AND  PHARYNX  189 

lymphoid  tissue  of  the  tonsil  is  extremely  common  in  childhood 
and  youth.  The  organ  may  enlarge  upwards,  downwards,  or 
medially,  and  may  possess  either  a  sessile  or  a  narrow  base. 

Modern  methods  of  enucleation  of  the  tonsil  endeavour  to 
remove  the  whole  organ,  and  sometimes  the  operation  is  so 
complete  that  the  pharyngeal  aponeurosis  is  in  part  taken  away 
and  the  superior  constrictor  muscle  is  exposed. 

The  blood-supply  of  the  tonsil  is  obtained  from  the  external 
maxillary  (facial)  through  its  ascending  palatine  and  tonsillar 
branches,  from  the  external  carotid  through  the  ascending 
pharyngeal  artery,  and  from  the  lingual  through  its  dorsales 
linguae  branches.  Severe  haemorrhage  sometimes  occurs  after 
enucleation,  and  it  has  been  attributed  (Merkel)  to  injury  of 
the  external  maxillary  artery.  This  vessel,  however,  can  only 
be  injured  when  the  muscular  wall  of  the  pharynx  has  been 
wounded. 

If  the  operation  is  performed  soon  after  an  attack  of  acute 
tonsillitis,  the  tonsillar  arteries  are  so  much  enlarged  that  they 
may  give  rise  to  a  haemorrhage  so  profuse  as  to  suggest  injury 
of  some  larger  vessel. 

The  lymph  vessels  of  the  palatine  tonsil  join  the  upper  anterior 
group  of  the  deep  cervical  lymph  glands.  Certain  members  of 
this  group  (p.  133)  rapidly  become  affected  in  acute  tonsillitis, 
and  in  malignant  disease  of  the  palatine  tonsil  the  glandular 
enlargement  attracts  the  patient's  attention  before  the  throat 
condition  gives  rise  to  any  marked  symptoms. 

The  Pharynx  is  situated  behind  the  nasal  fossae,  the  mouth, 
and  the  larynx.  Above,  it  is  roofed  in  by  the  base  of  the  skull, 
and  below,  it  becomes  continuous  with  the  oesophagus  opposite 
the  sixth  cervical  vertebra.  Its  lateral  and  posterior  walls  are 
supported  by  the  constrictor  muscles  (p.  190),  which  are  covered 
externally  by  the  bucco-pharyngeal  fascia.  Its  anterior  wall 
is  interrupted  by  the  choanae  (posterior  nares),  the  isthmus 
faucium,  and  the  upper  laryngeal  aperture  (Fig.  50).  Below 
the  last-named  it  is  only  separated  from  the  muscles  on  the 
posterior  surfaces  of  the  cricoid  and  arytenoid  cartilages  by  the 
mucous  membrane. 

The  Nasal  Pharynx  is  bounded  below  by  the  soft  palate, 
and  it  can  be  examined  by  the  finger,  introduced  through  the 
mouth,  and  carried  upwards  behind  that  structure.  On  its 
anterior  wall  the  posterior  border  of  the  nasal  septum  (p.  194) 
can  be  felt,  and  on  either  side  of  it  the  finger  can  be  passed 


190  THE  HEAD  AND  NECK 

through  the  choanae  so  as  to  touch  the  posterior  extremities  of 
the  inferior  and  middle  conchse  (turbinated  bones).  In  the 
adult  the  choanse  (posterior  nares)  measure  one  inch  long  and 
half  an  inch  wide,  but  in  the  child  the  relative  width  is  much 
greater.  In  the  roof  the  basilar  portion  of  the  occipital  bone 
can  be  felt,  and  half  an  inch  below,  on  the  posterior  wall,  the 
anterior  arch  of  the  atlas  can  be  recognised.  The  pharyngeal 
tonsil  is  situated  on  the  posterior  wall,  and  in  children  a  pro- 
liferation of  its  lymphoid  tissue  (adenoids)  may  fill  up  the  naso- 
pharynx and  render  nasal  breathing  impossible.  On  the  lateral 
wall  the  orifice  of  the  auditory  (Eustachian)  tube  leads  back- 
wards, laterally,  and  upwards  to  the  tympanum  (Fig.  50).  The 
posterior  lip  of  the  opening  forms  a  prominent  elevation — the 
tubal  projection  (Eustachian  cushion) — due  to  the  cartilaginous 
wall  of  the  tube,  and  behind  it  lies  the  pharyngeal  recess  (of 
Rosenmuller).  When  the  orifice  of  the  tube  is  occluded,  e.g. 
in  adenoids,  the  air  in  the  tympanic  cavity  gradually  becomes 
absorbed  and  deafness  results.  Inflation  of  the  tympanum  may 
be  carried  out  through  the  pharyngeal  orifice  of  the  tube  by 
means  of  a  Eustachian  catheter.  The  instrument  is  passed 
backwards  along  the  floor  of  the  inferior  meatus  until  the  down- 
turned  point  reaches  the  posterior  wall  of  the  nasal  pharynx. 
The  catheter  is  then  rotated  laterally  through  one  right  angle, 
and  in  this  way  its  point  is  lodged  in  the  pharyngeal  recess.  It 
is  then  slowly  withdrawn  from  the  nose  till  the  point  is  felt  to 
catch  on  the  tubal  projection.  Slight  upward  rotation  of  the 
point  at  this  stage,  accompanied  by  partial  withdrawal,  conducts 
it  past  the  obstruction,  and  if  it  is  now  directed  laterally  again, 
the  instrument  passes  into  the  orifice  of  the  auditory  tube. 

The  lymph  vessels  of  this  region  join  the  retro-pharyngeal 
lymph  glands  (p.  114)  and  the  upper  posterior  group  of  the  deep 
cervical  lymph  glands. 

The  Superior  Constrictor  Muscle  arises  mainly  from  the  pterygo-mandibular 
raphe,  and  is  on  the  same  plane  as  the  buccinator  (p.  176).  Its  upper  fibres 
are  inserted  into  a  tubercle  on  the  under  surface  of  the  basilar  part  of  the 
occipital  bone,  while  the  rest  of  the  muscle  is  inserted  into  a  median  raphe 
posteriorly.  The  Middle  Constrictor  Muscle,  which  overlaps  the  lower  part  of 
the  insertion  of  the  superior  constrictor,  arises  from  the  cornua  of  the  hyoid 
bone,  and  its  fibres  spread  out  as  they  pass  backwards  to  the  median  raphe. 
The  Inferior  Constrictor  arises  from  the  sides  of  the  thyreoid  and  cricoid 
cartilages.  The  lower  fibres  blend  with  the  muscular  wall  of  the  oesophagus, 
and  the  upper  fibres  overlap  the  lower  portion  of  the  middle  constrictor. 

The  constrictor  muscles  are  supplied  by  the  pharyngeal  plexus,  which 
is  formed  on  the  lateral  aspect  of  the  middle  constrictor  by  the  union!  of 
the  pharyngeal  branches  of  the  vagus  and  glosso-pharyngeal  nerves,  with 


THE  FACE,  MOUTH  AND  PHARYNX 


191 


branches  from  the  sympathetic  trunk.  The  sensory  portion  of  the  plexus  is 
distributed  to  the  whole  of  the  pharyngeal  mucous  membrane,  except  that 
covering  the  roof  and  the  adjoining  areas  of  the  lateral  walls,  which  is 
supplied  by  a  branch  from  the  spheno-palatine  ganglion  (p.  233). 

The  Oral  and  Laryngeal  Portions  of  the  Pharynx  lie  behind 
the  mouth,  the  dorsum  of  the  tongue,  and  the  larynx.  Later- 
ally they  are  related  to  the  great  vessels  of  the  neck,  and  pos- 
teriorly they  are  separated  from  the  bodies  of  the  upper  cervical 
vertebrae  by  the  retro-pharyngeal  and  prevertebral  layers  of 
fascia  and  the  longus  colli  muscles.  A  retro-pharyngeal  abscess 
(p.  114)  produces  a  swelling  of  the  posterior  pharyngeal  wall 
which  may  obstruct  the  passage  of  air  during  respiration,  causing 
symptoms  not  unlike  those  associated  with  adenoids  and  hyper- 
trophied  palatine  tonsils  (Fig.  37). 


Prosencephalon 

Median  nasal 
process 


Eye 
Stomatod?eum 


Globular  process 

Olfactory  pit 


FIG.  55. — The  Development  of  the  Face. 

Development  of  the  Face  and  Mouth. — About  the  thirteenth 
day  a  depression  appears  on  the  ventral  surface  of  the  embryo 
just  behind  the  anterior  cerebral  vesicle.  This  is  the  stomodceum 
or  primitive  mouth,  and  it  is  separated  from  the  foregut  by  the 
bucco-pharyngeal  membrane,  which  soon  breaks  down.  An 
elevation  appears  in  the  middle  line  of  the  roof  of  the  stomodceum 
— the  fronto-nasal  process — and  the  olfactory  pits  lie  on  each  side 
of  it.  These  pits  form  shallow  grooves  running  backwards  in 
the  roof  of  the  primitive  mouth,  and  they  become  bounded  in 
front  by  elevations  produced  by  the  lateral  and  median  nasal 
processes,  both  of  which  are  derived  from  the  fronto-nasal 
process.  The  mandibular  arches  (p.  148)  unite  to  complete  the 


192 


THE  HEAD  AND  NECK 


floor  of  the  stomodceum.  From  the  dorsal  part  of  the  man- 
dibular  arch  the  maxillary  process  grows  forwards,  but  above 
and  behind  it  is  separated  from  the  lateral  nasal  process  by  the 
naso-maxillary  fissure,,  a  part  of  which  subsequently  forms  the 
orbit  (Fig.  55). 

These  processes  fuse  so  that  the  median  nasal  process  gives 
rise  to  the  nasal  septum,  the  os  incisivum  (premaxilla),  and  the 
philtrum  (middle  third)  of  the  upper  lip.  The  lateral  nasal  pro- 
cesses form  the  roof  and  sides  of  the  nose,  while  the  maxillary 
processes  form  the  cheeks  and  the  remainder  of  the  upper  lip. 
At  a  later  date  the  palatal  processes  grow  medially  from  the 
maxillary  processes,  and  unite  with  the  remains  of  the  median 


Nasal  septum 


Inferior  conch; 


Anterior  cranial  fossa 


Crystalline  lem 
of  the  eyeball 


alatine  process 
ental  lamina 


Man 
Meckel's  cart 


Dental  lamina 


FIG.  56. — Frontal  Section  through  the  Face  ol  a  Human  Embryo 
at  the  Seventh  Week. 

nasal  process  and  with  one  another.  Fusion  occurs  anteriorly 
at  first  and  then  spreads  backwards. 

Prior  to  their  fusion,  the  lateral  nasal  and  maxillary  pro- 
cesses are  separated  from  one  another  by  a  groove  which  extends 
from  the  region  of  the  orbit  to  the  olfactory  pit.  This  groove 
becomes  converted  into  the  naso-lacrimal  (nasal)  duct,  but  if 
the  fusion  of  the  lateral  nasal  and  maxillary  processes  is  incom- 
plete, the  duct  opens  out  on  the  surface  of  the  face,  a  rare 
condition,  known  as  colobomafacialis. 

The  conditions  of  Harelip  and  Cleft  Palate  are  brought 
about  by  two  or  more  of  the  above-mentioned  processes  failing 


THE  FACE,  MOUTH  AND  PHARYNX  193 

to  unite  with  one  another.  In  the  simplest  variety,  the  maxillary 
process  of  one  side  fails  to  unite  with  the  mesial  nasal  process 
on  the  surface  only,  giving  rise  to  unilateral  harelip.  When  the 
failure  is  more  pronounced,  a  gap  exists  between  the  maxilla 
and  the  premaxilla  in  addition  to  the  harelip.  In  cleft  palate 
the  palatal  processes  have  failed  to  unite  with  one  another  or 
with  the  nasal  septum.  As  the  fusion  occurs  latest  posteriorly, 
the  bifid  uvula  is  the  simplest  variety  of  this  defect.  The  less 
complete  the  fusion,  the  further  forward  does  the  cleft  extend. 
Thus  the  palatal  processes  may  unite  with  the  mesial  nasal 
process  but  not  with  one  another,  in  which  case  the  cleft  is 
confined  to  the  soft  palate.  A  greater  degree  of  deformity  is 
seen  when,  in  addition  to  failure  of  the  palatal  processes  to  unite 
posteriorly,  one  palatal  process  has  failed  to  fuse  with  the  nasal 
septum.  In  this  case  the  floor  of  the  nasal  fossa  on  one  side  is 
wanting,  and  the  fossa  communicates  with  the  mouth.  Double 
cleft  palate  is  the  highest  degree  of  this  deformity.  It  is  found 
when  the  palatal  processes  fail  to  unite  with  one  another  pos- 
teriorly and  both  fail  to  unite  with  the  median  nasal  process 
(i.e.  nasal  septum  and  premaxilla).  The  os  incisivum  (pre- 
maxilla) separates  the  two  clefts  anteriorly  and  renders  the 
complete  cleft  Y-shaped.  In  these  cases  double  harelip  is  usually 
present  also,  and  the  clefts  extend  from  the  surface  to  the 
tip  of  the  uvula.  In  making  the  relief  incision  in  the  operation 
for  cleft  palate,  care  must  be  taken  not  to  cut  too  far  postero- 
medially,  lest  the  palatine  artery,  which  enters  the  posterior 
part  of  the  muco-periosteal  flap,  be  injured. 

In  making  a  prognosis  with  regard  to  the  after-results  of 
closure  of  a  cleft  palate,  the  shape  of  the  arch  must  be  taken 
into  consideration,  as  the  flaps  are  subjected  to  less  tension  when 
the  palatal  arch  is  pointed  than  when  the  arch  is  flat.  The 
degree  of  tension  may  be  diminished  by  fracturing  the  pterygoid 
hamulus  (hamular  process)  (Stiles).  By  this  means  the  tensor 
veli  palatini  (tensor  palati),  which  winds  round  the  bony  process, 
is  thrown  out  of  action. 

Development  of  the  Tongue. — Soon  after  the  appearance 
of  the  branchial  arches  (p.  148),  a  small  elevation,  the  tuber culum 
impar,  appears  in  the  floor  of  the  primitive  mouth.  Two  lateral 
swellings  arise  in  connection  with  the  mandibular  arches  and 
surround  and  fuse  with  the  tuberculum  impar.  In  this  way 
the  anterior  two  thirds  (or  oral  portion)  of  the  tongue  are  formed. 
About  the  same  time  a  transverse  ridge  appears  behind  the 

13 


194  THE  HEAD  AND  NECK 

tuberculum  impar  in  the  region  of  the  third  arch.  From  this 
the  posterior  third  (or  pharyngeal  portion)  of  the  tongue  is 
developed;  and  it  soon  unites  with  the  rest  of  the  organ.  The 
sensory  nerve-supply  of  the  tongue  indicates  the  complexity  of 
its  origin. 

The  anterior  two-thirds  are  supplied  with  ordinary  sensation 
by  the  lingual  and  with  special  sense  (taste)  by  the  chorda  tym- 
pani,  i.e.  by  branches  from  the  nerves  of  the  first  two  arches. 
The  posterior  third  is  supplied  by  the  nerve  of  the  third  arch, 
viz.  the  glosso-pharyngeal. 

The  Nose  and  Air  Sinuses. — The  development  of  the 
nose  has  already  been  outlined  on  p.  191 .  The  lateral  wall  of  the 
nasal  cavity  bears  the  three  conchce  (turbinated  bones),  which 
project  medially  and  downwards  so  as  to  separate  the  three 
meatuses  of  the  nose.  The  mucous  membrane  on  the  lateral  wall 
is  provided  with  a  freely  distensible  submucous  layer,  so  that 
such  conditions  as  hypertrophic  rhinitis  can  readily  occur.  Over 
the  septum,  which  forms  the  medial  wall  of  the  cavity,  the 
mucous  membrane  is  firmly  bound  down.  The  nerves  of 
ordinary  sensation  are  all  derived  from  the  spheno-palatine 
(Meckel's)  ganglion,  except  the  nasal  branch,  from  the  ophthal- 
mic, which  ramifies  on  the  septum.  The  olfactory  nerves  are 
distributed  to  the  mucous  membrane  in  the  upper  third  of  the 
cavity. 

Into  the  forepart  of  the  Inferior  Meatus  the  naso-lacrimal 
duct  opens  under  cover  of  the  inferior  concha.  The  Middle 
Meatus  receives  the  openings  of  the  infundibulum  from  the 
frontal  air  sinus,  the  anterior  and  middle  ethmoidal  cells,  and  the 
maxillary  sinus  (antrum  of  Highmore)  (Fig.  57).  The  two 
former  open  into  the  hiatus  semilunaris,  a  curved  depression  on 
the  lateral  wall.  The  bulla  ethmoidalis,  which  forms  a  part  of 
the  ethmoid  bone,  projects  into  the  middle  meatus  immediately 
above  the  hiatus.  It  contains  the  middle  ethmoidal  cells, 
which  open  at  its  upper  border.  The  Superior  Meatus  receives 
the  posterior  ethmoidal  air-cells ;  the  sphenoidal  air-cells  open 
into  a  small  depression  lying  above  and  behind  the  superior 
concha,  termed  the  recessus  spheno-ethmoidalis. 

The  Nasal  Septum  is  formed  posteriorly  by  the  vomer, 
antero-superiorly  by  the  perpendicular  plate  of  the  ethmoid, 
and  antero-inferiorly  by  the  septal  cartilage.  Deviation  of  the 
Septum  rarely  occurs  before  the  seventh  year.  It  may  involve 
the  cartilage  only,  or  both  bones  and  cartilage  may  be  deviated 


THE  FACE,  MOUTH  AND  PHARYNX  195 

to  one  or  other  side.  It  may  be  caused  by  excessive  growth  of 
the  vomer  and  the  perpendicular  plate  of  the  ethmoid,  and 
the  septum  buckles  along  the  line  of  their  articulation.  Over- 
growth of  the  septal  cartilage  alone  is  obstructed  posteriorly 
by  the  osseous  septum,  in  which  its  margins  are  firmly  fixed.  In 
this  case,  too,  deviation  occurs,  but  only  the  cartilaginous  part 
of  the  septum  is  affected.  Deviation  of  the  septum  may  result 
from  trauma,  and  it  tends  to  occlude  the  nasal  fossa  into  which 
it  projects. 

Fracture  of  the  nasal  bone  occurs  about  half  an  inch  above  its 
lower  margin  and  usually  leads  to  lateral  displacement  of  the 
nose ;  but  if,  in  addition,  the  perpendicular  plate  of  the  ethmoid 
is  broken,  the  nose  is  depressed  backwards.  These  fractures 
are  usually  compound  through  the  mucous  membrane,  and 
surgical  emphysema  is  apt  to  follow  if  the  patient  blows  his 
nose.  Owing  to  the  plentiful  blood-supply  of  the  parts,  rapid 
union  occurs,  and  it  is  therefore  important  that  the  fragments 
should  be  replaced  as  soon  as  possible  after  the  accident. 

The  Maxillary  Sinus  (Antrum  of  Highmore)  appears  during 
the  third  month  of  foetal  life  as  a  budding-out  from  the  mucous 
membrane  of  the  nasal  cavity  in  the  region  of  the  middle  meatus. 
It  grows  into  the  maxillary  process,  and  the  maxillary  bone  is 
formed  around  it. 

The  maxillary  sinus  is  roughly  pyramidal  in  shape.  Its 
apex  is  situated  at  the  zygomatic  (malar)  process,  and  its  base 
forms  the  lateral  wall  of  the  nasal  cavity.  Above,  it  is  roofed 
in  by  the  orbital  surface  of  the  maxilla,  which  is  channelled  by 
the  infra-orbital  nerve.  The  postero-lateral  wall  of  the  sinus 
forms  one  of  the  boundaries  of  the  infia-temporal  (zygomatic) 
fossa,  and  its  antero-lateral  wall  is  depressed  externally  to  form 
the  canine  fossa.  Inferiorly,  the  sinus  is  bounded  by  the  alveolar 
border,  and  the  roots  of  the  molar  and  premolar  teeth  form 
projections  in  its  floor.  The  walls  are  lined  by  muco-periosteum, 
which  is  continuous  with  the  mucous  membrane  of  the  middle 
meatus  of  the  nose  through  the  opening  of  the  sinus,  which  is 
placed  in  the  upper  part  of  its  medial  wall. 

Infection  may  reach  the  maxillary  sinus  directly  from  the 
middle  meatus,  or  it  may  ascend  through  the  floor  from  carious 
teeth.  When  pus  is  present  in  the  sinus,  the  natural  method 
of  drainage  into  the  middle  meatus  is  far  from  efficient,  as  the 
sinus  can  only  be  emptied  completely  when  the  head  is  bent  over 
to  the  opposite  side.  When  the  patient  lies  down,  the  pus 


196  THE  HEAD  AND  NECK 

trickles  down  the  middle  meatus  and  passes  into  the  naso- 
pharynx.   Assistance  in  the  diagnosis  is  obtained  by  the  use  of 


FIG.  57.  — Radiogram  of  Skull,  showing  normal  Maxillary  and 
Frontal  Sinuses. 

transillumination  and  radiograms.    In  both,  the  diseased  sinus 
is  more  opaque  than  the  healthy  one  (Fig.  58). 

The  sinus  may  be  approached  for  the  purpose  of  drainage  in 
three  ways  :  (a)  The  tooth  at  fault  may  be  extracted  and  a  hole 


THE  FACE,  MOUTH  AND  PHARYNX  197 

may  be  drilled  upwards  through  its  socket  into  the  sinus,    (b) 
The  lateral  wall  of  the  inferior  meatus  of  the  nose  may  b 
down  and  the  sinus  opened  into  through  its  base,     (c)  The  upper 
lip  may  be  everted  and  the  muco-periosteum  incised  over  t 


FIG.  58. — Empyaema  of  Maxillary  Sinus. 


canine  fossa.  A  hole  is  then  drilled  through  the  bone,  lateral 
to  the  ridge  produced  by  the  root  of  the  canine  tooth, 
drill  were  applied  to  the  medial  side  of  the  ridge,  the  inferior 
meatus  of  the  nose  would  be  opened  into  instead  of  the  sinus. 
Malignant  tumours  arising  from  the  muco-periosteal  lining 
of  the  maxillary  sinus  are  not  uncommon,  and  the  symptoms  to 
which  they  give  rise  depend  on  the  direction  in  which  they  grow. 


198  THE  HEAD  AND  NECK 

If  the  roof  of  the  sinus  is  pushed  upwards,  the  eye  becomes 
more  prominent,  and  neuralgia  may  occur  from  pressure  on  the 
infra-orbital  nerve.  The  pain  in  this  case  may  be  referred  over 
the  whole  distribution  of  the  trigeminal.  If  the  pressure  is 
mainly  exerted  on  the  medial  wall,  the  naso-lacrimal  duct 
is  obstructed,  causing  epiphora.  As  the  tumour  grows,  it 
pushes  its  way  into  the  nasal  fossa  and  blocks  that  side  of  the 
nose.  Forward  growth  obliterates  the  canine  fossa,  and  down- 
ward growth  invades  the  palate  and  gives  rise  to  a  swelling  in 
the  roof  of  the  mouth.  Owing  to  the  depth  of  the  infra-temporal 
fossa,  backward  growth  may  go  on  for  some  time  before  the 
presence  of  a  tumour  is  suspected. 

Eradication  of  malignant  disease  in  this  region  necessitates 
the  removal  of  the  whole  maxilla.  The  reader  should  follow 
on  the  skull  the  description  given  below,  as  it  is  important 
that  the  method  of  approach  should  be  clearly  understood, 
since  it  may  also  be  employed  for  removal  of  naso-pharyngeal 
fibro -sarcomata. 

Preliminary  laryngotomy  and  temporary  occlusion  of  the 
external  carotid  artery  materially  assist  the  surgeon  in  perform- 
ing this  operation. 

The  incision  begins  just  below  the  medial  palpebral  (internal 
tarsal)  ligament,  which  can  be  felt  quite  distinctly  at  the  medial 
angle  of  the  eye,  when  the  lateral  palpebral  commissure  (external 
canthus)  is  drawn  laterally.  It  passes  down  the  side  of  the  nose, 
round  the  ala  nasi,  and  down  through  the  upper  lip  into  the 
mouth  in  the  median  line.  The  horizontal  part  of  the  incision 
runs  along  the  lower  margin  of  the  orbit  to  the  zygomatic  bone, 
and  is  kept  parallel  to  the  branches  of  the  facial  nerve  (p.  178). 
If  the  external  .carotid  has  not  been  occluded,  the  cut  branches 
of  the  external  maxillary  artery  bleed  profusely,  as  the  incision 
is  at  once  carried  right  down  to  the  periosteum.  The  flap  is 
rapidly  elevated  from  the  maxilla,  and  the  reflection  of  the 
mucous  membrane  from  the  gum  to  the  cheek  is  divided,  so  that 
the  flap  may  be  turned  down,  kinking  the  external  maxillary 
artery,  and  thus  arresting  the  haemorrhage.  In  elevating  the 
flap,  the  orbicularis  oculi,  the  zygomaticus,  and  several  other 
facial  muscles  are  cut  through,  and  the  infra-orbital  nerve  and 
its  artery  are  divided  as  they  leave  the  foramen. 

In  the  next  step,  the  periosteum  is  elevated  from  the  orbital 
surface  of  the  maxilla.  It  must  be  preserved,  because  it  sub- 
sequently forms  a  support  for  .the  eye,  and  because  it  will  prevent 


THE  FACE,  MOUTH  AND  PHARYNX  199 

any  possible  sepsis  from  entering  the  orbit.  Further,  in  this 
way  the  origin  of  the  inferior  oblique  muscle  of  the  eye  can  be 
preserved  intact.  The  periosteum  is  elevated  over  the  floor 
of  the  orbit  until  the  inferior  orbital  (spheno-maxillary)  fissure 
is  reached.  A  Gigli  saw  is  passed  down  into  the  fissure  and 
brought  out  again  below  the  zygomatic  bone,  and  the  maxilla 
is  then  divided. 

The  attachment  of  the  lateral  nasal  cartilage  to  the  frontal 
(nasal)  process  of  the  maxilla  is  divided,  and  the  nose  can  then 
be  displaced  to  the  opposite  side.  One  blade  of  a  pair  of  large 
bone  forceps  is  passed  backwards  into  the  upper  part  of  the  nasal 
cavity,  and  the  other  blade  into  the  orbit  towards  the  medial 
end  of  the  inferior  orbital  fissure.  When  the  blades  are  ap- 
proximated, the  frontal  process  of  the  maxilla,  the  lacrimal 
bone,  and  the  ethmoidal  labyrinth  (lateral  mass)  are  divided, 
and  the  naso-lacrimal  duct  is  torn  through.  To  detach  the  bone 
from  its  attachments  posteriorly,  the  flap  must  be  well  retracted, 
so  that  a  chisel  may  be  inserted  into  the  groove  between  the 
maxilla  and  the  pterygoid  process  (plates)  of  the  sphenoid.  A 
slight  blow  will  effect  the  separation.  The  maxilla  is  still  held 
in  place  by  the  hard  palate,  which  has  yet  to  be  divided.  The 
mucous  membrane  is  cut  through  from  the  original  incision  in 
the  lip  backwards  across  the  gum  and  along  the  inner  border 
of  the  alveolus,  and  it  is  continued  round  the  last  molar  tooth 
to  join  the  incision  along  which  it  was  previously  split  between 
the  cheek  and  the  gum.  The  palatal  aponeurosis  and  the  velum 
palatinum  (soft  palate)  are  freed  from  the  posterior  margin  of 
the  hard  palate,  and  a  saw  is  passed  through  the  anterior  nares 
and  made  to  cut  downwards  into  the  mouth.  The  maxilla 
may  now  be  lifted  out  with  the  finger  and  thumb,  as  it  is 
only  attached  to  a  few  fibres  of  the  internal  pterygoid  and 
the  proximal  part  of  the  infra -orbital  nerve.  At  this  stage 
severe  haemorrhage  will  occur  from  the  alveolar  (dental) 
branches  of  the  internal  maxillary  artery  if  the  preliminary 
step  of  temporary  occlusion  of  the  external  carotid  has  not 
been  adopted. 

The  Zygomatic  (Malar)  Bone  may  be  fractured  by  direct 
violence  and  depressed  inwards.  It  may  be  levered  back  into 
position  by  a  strong  periosteum  detacher,  passed  upwards 
through  an  incision  in  the  mucous  membrane  along  the  line 
of  its  reflection  from  the  cheek  to  the  gum.  This  fracture  may 
be  associated  with  fracture  of  the  maxilla,  in  which  case  the 


200  THE  HEAD  AND  NECK 

maxillary  sinus  is  opened  into,  and  there  is  danger  of  surgical 
emphysema  occurring,  unless  the  patient  is  warned  not  to  blow 
his  nose. 

The  Frontal  Air  Sinus  arises  soon  after  birth  as  an  out- 
growth of  the  mucous  membrane  lining  the  middle  meatus  of 
the  nose,  but  it  does  not  begin  to  enlarge  until  the  seventh  year. 
It  grows  upwards  and  backwards,  and  penetrates  into  the  antero- 
medial  portion  of  the  orbital  part  of  the  frontal  bone.  The 
two  sinuses  are  separated  from  one  another  by  a  thin  septum, 
which,  although  median  below,  is  usually  deflected  to  one  or 
other  side  above.  According  to  Logan  Turner  the  average 
dimensions  of  the  frontal  sinus  are  :  Height,  from  the  fronto- 
maxillary  suture  upwards,  i  J  inches  ;  width,  from  the  septum 
laterally,  i  inch ;  depth,  from  the  surface  backwards,  between 
the  orbit  below  and  the  anterior  cranial  fossa  above,  f  inch. 
As  the  cavity  is  lined  with  muco-periosteum,  which  is  continuous 
with  the  nasal  mucosa,  the  sinus  may  be  infected  secondarily  to 
nasal  mischief.  On  the  other  hand  the  anterior  and  middle 
ethmoidal  cells  are  frequently  infected  by  direct  spread  from  a 
diseased  frontal  sinus.  The  infundibulum,  or  duct  of  the  sinus, 
is  not  disadvantageously  situated  for  drainage,  but,  owing  to 
small  bony  septa  which  may  be  present,  loculi  are  sometimes 
formed,  and  they  prevent  pus  from  draining  away  into  the 
nose. 

Empysema  of  the  Frontal  Sinus  can  be  recognised  by  trans- 
illumination  or  radiograms  (Fig.  59),  and,  by  these  means,  the 
position  of  the  septum  between  the  two  sinuses  can  be  ascertained. 
This  detail  is  of  extreme  importance,  as  the  surgeon  must  be 
certain  of  opening  the  infected  sinus  only.  Retained  pus  in 
the  frontal  sinus  may  find  its  way  through  the  floor  into  the  orbit, 
and  point  at  or  near  the  medial  palpebral  commissure  (inner 
canthus). 

The  sinus  is  approached  from  in  front  by  an  incision  which 
follows  the  eyebrow,  and  may  be  extended  medially  and  down- 
wards on  to  the  nose.  After  it  has  been  opened  up,  the  infun- 
dibulum is  enlarged  so  as  to  permit  the  passage  of  a  drainage 
tube  down  into  the  nose.  In  this  process  the  anterior  ethmoidal 
cells,  which  are  usually  affected,  are  broken  down,  and  the  an- 
terior extremity  of  the  inferior  concha  (turbinated  bone)  will 
probably  require  to  be  removed. 

Fractures  of  the  frontal  bone  may  open  into  the  frontal  sinus 
without  involving  the  cranial  cavity.  In  these  cases,  as  in 


THE  FACE,  MOUTH  AND  PHARYNX  201 

fracture  of  the  maxilla,  there  is  every  likelihood  of  surgical 
emphysema,  unless  the  patient  is  warned  against  blowing  his 
nose. 

The  Ethmoidal  Air-Cells  are  all  situated  in  the  ethmoidal 
labyrinth  (lateral  mass),  and  are  only  separated  from  the  orbit 


FIG.  59. — Empyaema  of  the  Left  Frontal  Sinus. 

by  the  thin  lamina  papyracea  (os  planum).  On  the  medial 
surface  of  the  labyrinth  are  the  projections  which  form  the 
superior  and  middle  conchse  (turbinated  bones).  The  anterior 
and  middle  ethmoidal  cells  open  into  the  middle  meatus,  and 
the  posterior  open  into  the  superior  meatus  of  the  nose. 

The  Sphenoidal  Sinuses  are  situated  in  the  body  of  the 
sphenoid  and  immediately  below  the  fossa  which    lodges  the 


202  THE  HEAD  AND  NECK 

hypophysis  (pituitary  body).  They  are  separated  from  one 
another  by  a  septum,  which  is  usually  deviated  to  one  or  other 
side  of  the  median  plane.  When  these  sinuses  become  infected, 
the  condition  may  spread  upwards  in  front  of  the  hypophysis 
(pituitary  body)  and  affect  the  optic  chiasma,  which  lies  above 
the  forepart  of  the  body  of  the  sphenoid ,  thus  giving  rise  to 
disturbance  of  vision.  Collections  of  pus  in  the  sphenoidal 


FIG.  60. — -Lateral  Radiogram  of  Skull.      The  relation  of  the  sphenoidal 
sinuses  to  the  hypophyseal  fossa  (selki  turcica)  is  well  shown. 

sinus  can  only  be  evacuated  properly  by  removal  of  its  anterior 
wall.  This  is  reached  through  the  posterior  ethmoidal  cells, 
which  are  usually  involved,  by  removal  of  the  middle  and 
superior  conchae  (turbinated  bones). 

Tumours  of  the  Hypophysis  (Pituitary  Body)  have  recently  been 
removed  through  the  sphenoidal  sinuses.  A  somewhat  U-shaped  incision 
is  made  round  the  nose,  which  is  turned  upwards  after  the  nasal  septum 
has  been  removed  and  the  lateral  nasal  cartilages  divided. 

By  taking  away  the  superior  and  middle  conchae,  better  access  can  be 
obtained.  At  a  depth  of  2^  inches  from  the  surface  the  resistance  of  the  an- 
terior wall  of  the  sphenoidal  sinuses  is  encountered,  and  the  wall  is  lightly 
chiselled  through.  The  septum  between  the  sinuses  is  remoyedj  and  th? 


THE  EYE 


203 


postero-superior  wall,  which  is  usually  much  thinned,  is  opened  very  carefully 
in  the  middle  line,  and  the  tumour  is  removed  piecemeal.  The  lateral  rela- 
tions of  the  hypophysis  (p.  225)  are  pushed  aside  by  the  growth  of  the  tumour 
and  run  little  risk  of  injury.  Lateral  radiograms  (Fig.  60)  clearly  demon- 
strate the  size  of  the  fossa  hypophyseos  (sella  turcica)  and  it  is  definitely 
enlarged  in  these  cases. 


THE  EYE. 

The  Eyelids. — The  eyelids  are  supported  by  the  tarsi  (tar sal 
plates),  which  consist  of  condensed  fibrous  tissue,  and  from 

Levator  palpebrse  superioris 
Superior  fornix  of  conjunctiva  ^  ^      ^ 

Ciliary  process 
nus  venosus  sclers 
Posterior  chamber 
Superior  tarsu 

Iris 

Cornea 

Anterior 

chamber 

Lens 

Inferior  tarsu 
Sinus  venosus  sclerse 

Zonula  ciliaris- 
Orbicularis  oculi 

Inferior  fornix  of  conjunctiv 

Hyaloid  canal 

FIG.  61. — Diagram  of  a  Sagittal  Section  through  the  Eye. 

their  margins  the  medial  and  lateral  palpebral  (tarsal)  ligaments 
extend  to  the  medial  and  lateral  borders  of  the  bony  orbit. 
Each  tarsus  is  separated  from  the  skin  by  a  muscular  layer 
and  subcutaneous  tissue,  and  the  latter,  being  very  loosely 
arranged,  is  readily  distended  by  effusions.  Further,  the  skin 
of  the  eyelid  is  so  thin  that  an  effusion  of  blood  into  the  sub- 
cutaneous tissue  becomes  apparent  at  once  as  a  "  black  eye." 
Numerous  sebaceous  glands  are  situated  in  the  free  margin  of 
the  eyelid,  and,  when  they  become  involved  in  suppurative 
inflammation,  they  give  rise  to  the  condition  known  as  a  "  stye." 
The  deep  surfaces  of  the  lids  are  lined  by  a  mucous  membrane, 


204  THE  HEAD  AND  NECK 

the  Conjunctiva,  which  is  reflected  from  them  on  to  the  anterior 
surface  of  the  eyeball.  The  lines  along  which  this  reflection 
takes  place  are  termed  the  superior  and  inferior  fornices  of  the 
conjunctiva.  Where  it  covers  the  cornea,  the  conjunctiva  is 
represented  by  a  translucent  layer  of  stratified  epithelium. 
The  upper  eyelid  may  be  everted  along  the  upper  border  of  the 
tarsus,  and  in  this  way  the  conjunctiva  on  its  surface  may  be 
exposed  for  the  purpose  of  removing  foreign  bodies.  E version 
of  the  lid  brings  into  view  the  tarsal  or  Meibomian  glands,  which 
appear  as  yellow  streaks  near  its  free  margin.  It  is  therefore 
from  this  surface  that  tarsal  cysts,  which  are  simply  obstructed 
tarsal  glands,  are  excised.  The  sensory  nerves  of  the  conjunctiva 
are  all  derived  from  the  trigeminal  (mainly  supra-orbital 
and  infra-orbital  branches).  Blepharo-spasm  and  lacrimation 
may  be  caused  reflexly  by  the  presence  of  foreign  bodies  or 
by  an  inflammatory  condition  of  the  conjunctival  sac.  In 
paralysis  of  the  trigeminal,  conjunctivitis  or  corneal  ulceration 
frequently  results  from  the  presence  of  particles  of  dirt,  which 
are  unrecognised  owing  to  the  loss  of  sensibility.  Ultimately, 
the  intra-ocular  structures  become  affected  and  pan-ophthalmitis 
ensues. 

The  arterial  supply  of  the  lids  is  derived  from  the  ophthalmic 
artery.  The  corresponding  veins  communicate  with  the  oph- 
thalmic veins,  which  join  the  cavernous  sinus,  and  also  with  the 
superficial  temporal  and  anterior  facial  veins.  On  account  of 
the  existence  of  this  double  channel  of  return,  effusions  into  the 
eyelids  are  absorbed  with  great  rapidity.  Both  lids  contain 
a  rich  network  of  lymph  vessels,  and,  as  a  result,  drugs  placed  in 
the  conjunctival  sac,  in  the  form  of  lamellae,  are  quickly  absorbed. 
From  the  lateral  half  of  the  lids  the  lymph  vessels  pass  to  the 
anterior  auricular  lymph  gland,  while  those  from  the  medial 
half  follow  the  course  of  the  anterior  facial  vein,  and  pass  through 
the  facial  lymph  glands,  before  terminating  in  the  submaxillary 
lymph  glands. 

The  tarsi  are  connected  to  the  upper  and  lower  margins  of 
the  orbit  by  fibrous  tissue,  which  forms  a  sheet  sufficiently  strong 
to  delay  a  retro-tarsal  haemorrhage  from  passing  forwards  into 
the  subcutaneous  tissue  of  the  eyelid.  In  fracture  of  the  skull 
involving  the  roof  of  the  orbit,  vthe  haemorrhage  appears  first 
under  the  margins  of  the  conjunctiva,  and  then  spreads  in  a 
fan-shaped  manner  towards  the  cornea.  The  blood  remains 
red  owing  to  the  thinness  of  the  conjunctiva  and  the  consequent 


THE  EYE 


205 


transfusion  of  oxygen  from  the  air.  The  haemorrhage  may 
descend  between  the  superior  tarsus  and  the  conjunctiva,  and 
subsequently  appear  at  the  margin  of  the  upper  eyelid.  Finally, 
it  may  ascend  on  the  outer  surface  of  the  tarsus  and  become 
subcutaneous. 

Subconjunctival  haemorrhage  may  arise  from  the  con- 
junctival  vessels  as  the  result  of  a  blow  on  the  eye,  but  in  these 
cases  the  haemorrhage  begins  near  the  cornea. 

The  Lacrimal  Gland  lies  in  contact  with  the  antero-lateral 
part  of  the  roof  of  the  orbit.  Its  posterior  portion  rests  on  the 
eyeball,  but  an- 


'  Lacrimal  puncta 
Lacrimal  ducts 


Lacrimal  sac 


Naso-lac 


Maxillary  sinu 

Plica  lacrimalis 

Inferior  tneatus 


FIG.  62. — Diagram  of  the  Naso-lacrimal  Duct 
and  its  Connections. 


teriorly  it  is  in  con- 
tact with  the  superior 
fornix  of  the  con- 
junctiva, and  this 
portion  of  the  gland 
can  just  be  made 
out  when  the  upper 
eyelid  is  everted. 
Numerous  small 
ducts  leave  the  gland 
and  open  into  the 
conjunctivalsac  near 
the  superior  fornix. 
The  tears  pass  across 
the  eyeball  by  the 
action  of  gravity, 
aided  by  the  periodic 
contractions  of  the 

orbicularis  oculi,  and  reach  the  puncta  on  the  medial  side.  These 
are  small  openings  placed  on  the  summits  of  papillae,  which  are 
situated  on  the  free  margins  of  the  lids  near  their  medial  ex- 
tremities. They  are  kept  in  apposition  with  the  conjunctiva  by 
the  action  of  the  inferior  tarsal  (tensor  tarsi)  muscle,  which  is 
a  part  of  the  orbicularis  oculi,  and  is  supplied  by  the  facial 
nerve.  The  condition  of  epiphora  results  from  the  paralysis  of 
this  muscle.  The  puncta  lead  into  the  lacrimal  ducts,  which  at 
first  run  for  a  short  distance  at  right  angles  to  the  lid  margins, 
and  then  turn  medially  to  enter  the  lacrimal  sac  (Fig.  62). 

The  Lacrimal  Sac  lies  behind  the  medial  palpebral  (tarsal) 
ligament.  Abscesses  in  the  sac  should  be  incised  just  below 
the  ligament,  the  position  in  which  they  usually  point,  and 


206  THE  HEAD  AND  NECK 

lateral  to  the  termination  of  the  external  maxillary  artery 
(Stiles).  The  upper  end  of  the  sac  is  blind,  but  below  it  narrows 
to  form  the  naso-lacrimal  duct,  which  opens  into  the  inferior 
meatus  of  the  nose.  This  duct  is  about  half  an  inch  long,  and 
its  lower  end  is  protected  by  a  fold  of  mucous  membrane  (the 
plica  lacrimalis).  In  cases  of  epiphora  where  a  blockage  of  the 
naso-lacrimal  duct  is  suspected,  a  probe  may  be  passed  along  it 
from  its  upper  end.  The  lower  lid  is  everted,  and  the  probe  is 
entered  at  the  punctum  and  passed  in  for  a  short  distance.  It 
is  then  passed  medially  along  the  duct  into  the  lacrimal  sac  until 
its  medial  wall  is  encountered.  The  hand  is  then  elevated  so 
that  the  point  of  the  probe  is  made  to  pass  downwards  and 
slightly  backwards  and  laterally  into  the  nose.  The  direction 
of  the  naso-lacrimal  duct  is  indicated  by  a  line  joining  the  medial 
palpebral  commissure  (inner  canthus)  to  the  interval  between 
the  first  molar  and  the  second  premolar  tooth. 

The  Orbit  and  Eyeball.— The  Fascia  Bulbi  (Capsule  of 
Tenon)  is  a  layer  of  fascia  which  almost  completely  surrounds 
the  eyeball,  and  is  continuous  with  the  sheath  of  the  optic 
nerve  behind.  Anteriorly,  it  lies  deep  to  the  conjunctiva  and 
terminates  at  the  corneo-scleral  junction.  The  bellies  of  the 
orbital  muscles  lie  outside  the  fascia,  but  their  tendons  pierce 
it  to  gain  insertion  into  the  sclera,  and  the  fascia  is  prolonged 
backwards  upon  them  to  fuse  with  the  muscle  sheaths.  These 
prolongations  are  particularly  strong  in  relation  to  the  lateral 
and  medial  rectus  muscles,  and  they  are  connected  to  the  walls 
of  the  orbit,  an  arrangement  which  checks  lateral  and  medial 
rotation  of  the  eye  (check  ligaments}.  They  are  connected  to 
one  another  by  a  thickened  part  of  the  fascia  bulbi  which  lies 
below  the  eye,  forming  the  suspensory  ligament  of  Lockwood. 
It  is  this  band,  together  with  the  orbital  periosteum,  which 
supports  the  eyeball  after  excision  of  the  maxilla  (p.  198). 

The  Muscles  of  the  Orbit. — The  Levator  Palpebrce  Superioris 
lies  immediately  under  the  orbital  roof.  It  is  supplied  by  the 
oculo-motor  nerve,  and  when  that  nerve  is  paralysed  the  con- 
dition of  ptosis  results.  The  Superior  Rectus  rotates  the  eyeball 
upwards  and  medially.  It  acts  in  unison  with  the  Inferior 
Oblique,  which  rotates  the  eyeball  upwards  and  laterally.  Both 
are  supplied  by  the  oculo-motor  nerve.  The  Inferior  Rectus 
rotates  the  eyeball  downwards  and  medially,  and  acts  in  unison 
with  the  Superior  Oblique,  which  rotates  it  downwards  and 
laterally.  The  former  is  supplied  by  the  oculo-motor  and  the 


THE  EYE  207 

latter  by  the  trochlear  nerve.  The  Lateral  Rectus,  supplied  by 
the  abducent  nerve,  and  the  Medial  Rectus,  supplied  by  the 
oculo-motor,  produce  lateral  and  medial  rotation  of  the  eyeball. 
Motor  Nerves  of  the  Orbit. — The  Oculo-motor  (third  cerebral) 
nerve  supplies  all  the  orbital  muscles  except  the  superior  oblique 
and  the  lateral  rectus.  In  addition  it  gives  off  the  short  (motor) 
root  of  the  ciliary  (lenticular)  ganglion,  and  in  this  way  supplies 
the  ciliary  muscle  and  the  sphincter  pupillse.  In  complete 
paralysis  of  the  oculo-motor  nerve,  the  pupil  is  widely  dilated 
by  the  dilatator  pupillse  (supplied  by  the  sympathetic)  and 

Supra-orbital  nerve 
Levator  palpebrae  superioris  |  Ophthalmic  vein 

Roof  of  orbit    •    ;  ; 

Superior  rectus      '        i  i  Supra-trochlear  nerve 
Trochlear  nerve 
;    Superior  oblique 

Naso-ciliary  nerve 

Lacrimal  n^^J^^^fUS^Sf     <ifck><         -  Ophthalmic  artery 


Abducent  nerve 


Oculo-motor  nerve,  Jf^\ 
lower  division 


Middle  concha 
-     Maxillary  sinus 


Infra-orbital  nerve        |     Ophthalmic  vein 
Inferior  rectus 


FIG.  63.  —  Frontal  Section  through  the  Orbit,  to  show  the  relative 
positions  of  the  Muscles,  Vessels  and  Nerves. 

does  not  react  to  light.  The  power  of  accommodation  to  dis- 
tance is  lost,  and  ptosis  is  present.  Owing  to  the  unopposed 
action  of  the  lateral  rectus,  which  is  not  involved,  a  divergent 
strabismus  results,  and  the  patient  carries  his  head  rotated  to 
the  opposite  side  in  order  to  compensate  for  his  disability. 

The  Trochlear  (Fourth  Cerebral)  Nerve  supplies  the  superior 
oblique  only.  Paralysis  of  this  nerve  produces  diplopia,  when 
the  patient  looks  downwards,  because,  while  pure  downward 
rotation  is  possible  in  the  sound  eye,  the  inferior  rectus  imparts 
a  medial  as  well  as  a  downward  direction  to  the  eye  on  the  affected 
side,  and  the  superior  oblique,  which  should  counteract  the 
medial  rotation,  is  paralysed. 

The  Abducent  (Sixth  Cerebral)  Nerve  supplies  the  lateral  rectus 


208  THE  HEAD  AND  NECK 

muscle.  When  it  is  paralysed,  the  medial  rectus  is  unopposed 
and  a  convergent  strabismus  results.  In  an  endeavour  to  com- 
pensate for  this  disability,  the  patient  carries  his  head  rotated 
to  the  affected  side. 

In  the  intracranial  part  of  their  course  the  motor  nerves  of 
the  orbit  may  be  pressed  on  by  the  exudate  of  a  basal  meningitis 
(p.  225),  by  haemorrhage  following  fractures  of  the  base  of  the 
skull,  or  by  thrombosis  of  the  cavernous  sinus  as  they  lie  in  its 
lateral  wall  (p.  225). 

Tenotomy  of  the  Ocular  Tendons  is  performed  in  cases  of 
strabismus  which  are  due  to  congenital  shortening  of  the  medial 
or  lateral  rectus  muscles.  An  incision  is  made  through  the 
conjunctiva  near  the  margin  of  the  cornea,  and  the  underlying 
fascia  bulbi  (capsule  of  Tenon)  is  opened.  A  blunt  hook  may  be 
inserted  through  the  wound,  and  the  desired  tendon  can  be 
drawn  forwards  and  divided. 

The  Ophthalmic  Artery  is  a  branch  of  the  internal  carotid.  It 
supplies  the  muscles  of  the  orbit,  the  lacrimal  gland,  and  the 
eyelids.  Ciliary  branches  supply  the  eyeball,  and  the  arteria 
centralis  retinae,  which  runs  forwards  in  the  optic  nerve,  is 
distributed  to  the  retina. 

The  Ophthalmic  Veins  communicate  with  the  pterygoid 
venous  plexus  through  the  inferior  orbital  (spheno-maxillary) 
fissure,  and  with  the  anterior  facial  vein  (p.  175).  They  pass 
backwards  through  the  superior  orbital  (sphenoidal)  fissure  and 
join  the  cavernous  sinus. 

The  Eyeball.— The  Sclera,  a  strong  fibrous  membrane, 
forms  the  outermost  coat  of  the  eye.  Anteriorly,  it  lies  deep  to 
the  conjunctiva  and  the  fascia  bulbi  and  blends  with  the  cornea. 
It  is  supplied  by  branches  from  the  ciliary  arteries,  and  as  these 
vessels  approach  the  corneo-scleral  junction  they  send  out 
branches  into  the  episcleral  tissue,  which  form  anastomosing 
loops  close  to  the  margin  of  the  cornea.  From  these  loops 
numerous  small  straight  branches  pass  into  the  periphery  of  the 
cornea,  where  they  anastomose  with  one  another.  In  inflam- 
mation of  the  sclera  these  vessels  become  visible,  and  form  the 
"  zone  of  ciliary  injection." 

The  Cornea  consists  mainly  of  modified  connective  tissue. 
Except  at  its  extreme  edge,  it  is  non-vascular,  but  it  is  well 
provided  with  spaces  containing  lymph,  on  which  it  depends  for 
its  nutrition.  The  lymph  is  drained  from  the  cornea  by  the 
sinus  venosus  sclerce  (canal  of  Schlemni). 


THE  EYE  209 

In  repair  of  inflammatory  conditions  of  the  cornea,  the 
newly  formed  connective  tissue,  not  being  specialised,  may 
cause  opacities,  which  vary  in  degree  from  nebulae  to  leucoma. 
Iridectoiny  may  be  of  value  in  certain  cases,  as  it  offers  a  larger 
aperture  for  the  transmission  of  light. 

Internal  to  the  sclera  is  the  Chorioid,  which  supports  the 
ciliary  vessels  and  contains  numerous  pigment  cells.  Anteriorly, 
the  chorioid  is  continuous  with  the  Ciliary  Body  and  the  Iris. 
The  iris  separates  the  anterior  from  the  posterior  chamber  of 
the  eye.  Its  peripheral  attachment  is  continuous  behind  with 
the  ciliary  body  and  in  front  with  the  deepest  layer  of  the  cornea, 
which  it  meets  at  an  acute  angle.  A  circular  channel,  the  sinus 
venosus  sclerse  (of  Schlemm),  is  placed  in  the  corneo-scleral 
junction  immediately  opposite  the  angle  between  the  iris  and 
the  cornea  (Fig.  61).  The  sinus  is  surrounded  by  numerous 
lymph  spaces,  through  which  the  aqueous  humour  and  the 
lymph  from  the  cornea  communicate  with  it  and  indirectly  with 
the  ciliary  veins.  Obliteration  of  this  angle  by  the  formation  of 
adhesions  prevents  the  proper  drainage  from  the  aqueous 
humour,  and  causes  increased  intra-ocular  tension  and  glaucoma. 
The  iris  is  richly  supplied  with  blood,  and  the  ciliary  arteries 
form  anastomosing  circles  at  its  free  and  attached  margins. 

The  optic  nerve  pierces  the  retina  at  a  point  a  little  medial  to  the  posterior 
pole  of  the  eyeball.  The  papilla  of  the  optic  nerve  (optic  disc)  is  the  physio- 
logical "  blind  spot  "  of  the  retina.  With  the  aid  of  the  ophthalmoscope, 
the  central  artery  of  the  retina  can  be  seen  on  the  papilla  breaking  up  into  its 
terminal  branches.  In  all  mammals  which  have  binocular  vision,  the  point 
on  the  retina  through  which  the  antero-posterior  axis  of  the  eyeball  passes 
is  highly  specialised,  and  is  known  as  the  macula  lutea. 

The  Vitreous  Body,  which  occupies  the  greater  part  of  the  posterior  chamber 
of  the  eye,  is  surrounded  by  the  hyaloid  membrane.  In  front,  the  membrane 
is  attached  to  the  ciliary  body,  and  divides  to  form  the  suspensory  ligament 
which  encloses  the  Crystalline  Lens.  When  the  ciliary  muscle,  which  is  con- 
tained in  the  ciliary  body,  contracts,  the  suspensory  ligament  is  drawn 
forwards,  and  the  pressure  which  it  exerts  on  the  anterior  surface  of  the  lens 
is  diminished.  As  a  result,  this  surface  becomes  more  convex,  and  diverging 
rays  of  light  become  focussed  on  the  retina. 

The  diameter  of  the  crystalline  lens  is  one-third  of  an  inch,  and  this 
measurement  must  be  remembered  in  making  the  incision  in  the  corneo- 
scleral  junction  for  its  removal. 


THE    AUDITORY  APPARATUS. 

Development. — The  outer  cartilaginous  portion  of  the  ex- 
ternal acoustic  meatus  is  derived  from  the  dorsal   part  of  the 

14 


210  THE  HEAD  AND  NECK 

first  visceral  cleft,  and  the  auricle  is  formed  by  the  development 
and  fusion  of  several  tubercles,  which  arise  from  the  mandi- 
bular  and  hyoid  (first  and  second)  arches.  This  double  origin 
is  indicated  in  the  adult  by  the  double  nerve  supply  from  the 
auriculo-temporal  and  great  auricular  nerves  (pp.  108,  174). 
Owing  to  faulty  union  of  the  various  tubercles  with  one  another, 
pre-auricular  fistulse  may  occur.  The  interval  between  the 
helix  and  the  tragus  is  the  commonest  site  of  this  congenital 
deficiency,  and  it  is  said  to  indicate  the  line  of  union  between 
the  first  and  second  arches. 

The  Tympanum  or  Tympanic  Cavity  and  the  Auditory  (Eustachian)  Tube 
are  the  remains  of  the  first  visceral  pouch  (Fig.  46).  They  are  enclosed  in  the 
temporal  bone,  which  consists  of  three  pieces  at  birth.  The  Petromastoid 
Portion  encloses  the  internal  ear,  and  forms  the  medial  part  of  the  roof  and 
the  medial  wall  of  the  tympanum,  the  osseous  part  of  the  auditory  tube,  and 
the  tympanic  (mastoid)  antrum.  The  Squamous  Portion  forms  part  of  the 
lateral  wall  of  the  skull  and  of  the  tympanum,  and  the  upper  part  of  the 
osseous  external  acoustic  meatus.  It  also  forms  the  lateral  wall  of  the 
tympanic  antrum  and  the  lateral  part  of  the  roof  of  the  tympanum.  The 
Tympanic  Ring  forms  the  remainder  of  the  osseous  external  meatus. 
Although  the  tympanic  antrum  is  present  at  birth,  the  mastoid  process  does 
not  begin  to  develop  until  the  end  of  the  second  year,  and  the  mastoid  air- 
cells  begin  to  appear  as  outgrowths  from  the  antrum  at  the  same  period. 

The  External  Acoustic  Meatus  leads  from  the  concha  to  the 
membrana  tympani.  Its  lateral  cartilaginous  portion  is  first 
directed  medially,  forwards  and  upwards,  and  then,  at  a  distance 
of  about  a  quarter  of  an  inch  from  the  surface,  medially  and 
backwards  to  meet  the  osseous  portion  of  the  meatus,  which  is 
directed  medially,  downwards  and  forwards.  The  membrana 
tympani  is  obliquely  placed  so  that  the  lower  and  anterior  walls 
of  the  canal  are  definitely  longer  than  the  upper  and  posterior. 
The  total  length  of  the  meatus  is  about  one  inch,  and  its 
narrowest  part  is  found  at  three-quarters  of  an  inch  from  the 
surface.  In  the  examination  of  the  tympanic  membrane  the 
canal  is  straightened  by  drawing  the  auricle  upwards  and  back- 
wards. This  procedure  brings  the  cartilaginous  portion  into  line 
with  the  osseous  portion,  but  in  the  infant  the  auricle  must  be 
drawn  downwards  and  backwards,  as  the  canal  is  almost  entirely 
cartilaginous,  and  the  outer  surface  of  the  membrana  tympani 
is  directed  mainly  downwards. 

The  external  acoustic  meatus  is  lined  by  a  layer  of  skin, 
which  is  reflected  over  the  outer  surface  of  the  tympanic  mem- 
brane. It  is  firmly  bound  down  to  the  periosteum  and  peri- 
chondrium,  and  therefore  septic  infections  of  the  canal,  although 


THE  AUDITORY  APPARATUS  211 

causing  little  swelling,  give  rise  to  severe  pain.  Chronic  in- 
flammatory processes  may  stimulate  the  periosteum  to  such  an 
extent  that  the  new  bone  may  occlude  the  canal  almost  entirely. 
The  cuticular  lining  is  supplied  by  branches  from  the  auriculo- 
temporal  nerve  (p.  174)  and  the  auricular  branch  of  the  vagus. 
Stimulation  of  the  latter  nerve,  by  foreign  bodies  or  collections 
of  wax,  may  produce  symptoms  so  divergent  as  cough  (internal 
laryngeal  nerve,  p.  159)  and  dyspepsia  (terminal  branches  of 
vagus,  p.  298).  Similar  irritation  of  the  auriculo-temporal 
nerve  gives  rise  to  pain,  which  may  be  referred  to  the  side  of 
the  head,  to  the  teeth  of  the  mandible,  etc. 

The  cuticular  lining  of  the  canal  possesses  numerous  cerumin- 
ous  glands ;  and  the  wax  which  they  secrete  is  normally  carried 
to  the  exterior  by  the  movements  of  the  mandibular  condyle, 
which  presses  against  the  anterior  wall  of  the  meatus.  Sudden 
deafness  sometimes  follows  the  entrance  of  water  into  the  canal, 
as  it  is  readily  absorbed  by  the  wax,  which  swells  up  in  con- 
sequence. 

The  Membrana  Tympani  lies  at  the  bottom  of  the  external 
acoustic  meatus,  and  forms  the  greater  part  of  the  lateral  wall 
of  the  tympanic  cavity.  It  consists  of  an  outer  cutaneous,  an 
inner  mucous,  and  an  intermediate  fibrous  layer.  It  is  very 
obliquely  placed,  so  that  its  outer  surface  looks  laterally,  down- 
wards and  slightly  forwards,  i.e.  the  antero-inferior  portion  is 
furthest  removed  from  the  surface. 

When  a  normal  tympanic  membrane  is  examined  with  the 
aid  of  reflected  light,  a  well-marked  depression,  the  umbo,  can. 
be  recognised  at  a  little  below  its  centre.  When  the  auditory 
tube  is  obstructed  the  air  in  the  tympanum  becomes  absorbed, 
and  the  normal  concavity  is  accentuated.  The  handle  of  the 
malleus,  which  is  attached  to  the  fibrous  layer  of  the  membrane, 
can  be  traced  upwards  and  forwards  from  the  umbo  to  a  small 
prominence,  which  is  produced  by  the  lateral  (short)  process 
of  the  malleus.  From  this  point  the  anterior  and  posterior 
malleolar  folds  diverge  in  an  upward  direction,  and  bound  the 
flaccid  part  of  the  membrane  (Fig.  64).  The  cms  longum  (long 
process)  of  the  incus  may  be  discerned  lying  behind  and  parallel 
to  the  handle  of  the  malleus,  though  it  lies  on  a  deeper  plane. 
A  cone  of  reflected  light  extends  from  the  umbo  over  the  antero- 
inferior  part  of  the  membrane,  and  serves  as  a  guide  to  the  site 
of  puncture  in  the  operation  of  paracentesis  tympani,  which  is 
carried  out  through  the  postero-inferior  quadrant.  This  part  of 

14  a 


212 


THE  HEAD  AND  NECK 


the  membrane  is  selected  because  it  is  furthest  removed  from  the 
handle  of  the  malleus  and  the  chorda  tympani,  and  because  it 
affords  good  drainage.  The  nerve  runs  downwards  and  forwards 
across  the  deep  surface  of  the  membrane,  lateral  to  the  crus 
longum  of  the  incus,  but  medial  to  the  neck  of  the  malleus. 
The  point  of  the  knife  must  not  be  pushed  too  deeply  through 
the  membrane  as  the  tympanum  is  only  one-eighth  of  an  inch 
wide  at  this  point,  and  the  fenestra  of  the  cochlea  (fenestra 
rotunda),  which  lies  on  its  medial  wall,  may  be  injured. 

The  Tympanum  is  about  half  an  inch  in  length,  and  varies 
from  a  tenth  to  a  sixth  of  an  inch  in  width.  Its  uppermost  part, 
known  as  the  Epitympanic  Recess  (Attic),  lies  above  the  level  of 


Membrana  flaccida 

Anterior  malleolar 

plica 


Manubrium  mallei 

Antero-superior 
quadrant 


Antero-inferior 
quadrant 


Posterior  malleolar 

plica 

Lateral  process  of 

malleus 

Long  crus  of  incus 

Postero-superior 
quadrant 

Postero- inferior 
quadrant 

Cone  of  light 


FiG.  64. — Left  Tympanic  Membrane  (as  viewed  from  the  external 
acoustic  meatus).      x  3. 

the  tympanic  membrane,  and  contains  the  head  of  the  malleus 
and  the  body  of  the  incus. 

The  Anterior  Wall  of  the  tympanum  is  formed  by  a  thin 
plate  of  bone,  which  separates  the  tympanic  cavity  from  the 
carotid  canal.  In  the  lateral  part  of  this  wall  is  situated  the 
opening  of  the  auditory  tube,  which  leads  downwards,  forwards, 
and  medially  to  the  nasal  pharynx.  In  the  child  the  direction 
of  the  tube  is  practically  horizontal,  the  downward  inclination 
being  very  slight.  The  Koof  is  formed  by  the  legmen  tympani, 
which  separates  the  tympanum,  the  auditory  tube,  and  the 
tympanic  (mastoid)  antrum  from  the  middle  cranial  fossa  and 
the  temporal  lobe  of  the  brain.  Its  lateral  border  corresponds 
to  the  line  of  the  petro-squamous  suture,  which  may  remain 
unossified  until  the  end  of  the  second  year.  Up  to  that  age 
inflammatory  conditions  of  the  brain  or  meninges  may  be  caused 


THE  AUDITORY  APPARATUS 


213 


by  the  upward  spread  of  infection  from  the  tympanum  along 
the  veins  which  traverse  the  suture  and  terminate  in  the  superior 
petrosal  sinus.  The  narrow  Floor  of  the  tympanum  is  formed 
by  the  bone  of  the  jugular  fossa,,  and  lies  below  the  level  of  the 
lower  border  of  the  tympanic  membrane.  It  is  pierced  by  a 
few  small  veins,  which  pass  from  the  mucous  membrane  lining 
the  cavity  to  join  the  internal  jugular  vein.  Septic  thrombosis 
of  the  latter  may  follow  this  course  in  otitis  media.  On  the 
Medial  Wall,  which  separates  the  tympanum  from  the  internal 
ear,  a  slight  elevation  is  present.  It  is  produced  by  the  first 
coil  of  the  cochlea,  and  is  termed  the  promontory.  The  fenestra 
of  the  cochlea  (fenestra  rotunda)  is  situated  below  and  behind 


Tympanic  antrum 


Fenestra  vestibuli 


Incus 


Head  of  malleus 
Tegmen  tympani 
Chorda  tympani 

Auditory  tube 


Promontory 

Fenestra  cochleae 

Facial  canal 


I         T-"     Tympanic  membrane 
Facial  canal 


FIG.  65. — Section  through  a  Left  Temporal  Bone  along  the  line  of  the 
Tegmen  Tympani. 

the  promontory,  and  in  life  it  is  closed  by  a  membrane  which 
separates  the  tympanic  cavity  from  the  scala  tympani  of  the 
cochlea.  The  fenestra  of  the  vestibule  (fenestra  ovalis)  is  placed 
at  a  slightly  higher  level.  It  is  closed  by  the  base  (foot-plate) 
of  the  stapes.  The  canal  for  the  facial  nerve  produces  a  ridge, 
which  passes  backwards  above  the  promontory  and  downwards 
behind  it  (Fig.  65).  The  Lateral  Wall  is  formed  mainly  by 
the  tympanic  membrane  (p.  211).  In  the  upper  and  medial 
part  of  the  Posterior  Wall  the  epitympanic  recess  communicates 
with  the  tympanic  (mastoid)  antrum  through  a  short  passage, 
which  is  known  as  the  aditus.  The  medial  wall  of  the  aditus 
is  crossed  by  the  descending  part  of  the  ridge  produced  by  the 
facial  nerve,  and  just  above  the  ridge  there  is  a  slight  promi- 
nence due  to  the  lateral  semicircular  canal.  It  is  through  the 

14  b 


214  THE  HEAD  AND  NECK 

aditus  that  infection  reaches  the  tympanic  antrum  from  the 
tympanic  cavity. 

The  Auditory  Ossicles. — The  handle  of  the  malleus  is  very  intimately 
connected  to  the  membrana  tympani.  Waves  of  sound  impinging  on  the 
membrane  thrust  the  malleus  medially,  and  the  movement  is  conveyed  through 
it  to  the  incus  and  stapes.  Medial  movements  of  the  stapes  set  up  a  wave 
in  the  perilymph  of  the  scala  vestibuli,  and  this  wave  passes  up  the  cochlea 
to  the  scala  tympani.  In  the  cochlea  it  stimulates  the  spiral  organ  of  Corti, 
and  it  is  dissipated  below,  where  it  impinges  on  the  membrane  which  closes 
the  fenestra  of  the  cochlea  (fenestra  rotunda). 

The  Tensor  Tympani  occupies  a  small  canal  immediately  above  the 
auditory  tube.  Its  tendon  is  inserted  into  the  upper  part  of  the  handle  of 
the  malleus,  and  its  contractions  draw  the  bone  medially,  thus  rendering  the 
tympanic  membrane  tense.  It  is  supplied  by  a  branch  from  the  otic  ganglion, 
which  lies  on  the  lateral  wall  of  the  nasal  pharynx,  and  obtains  its  motor  fibres 
from  the  mandibular  division  of  the  trigeminal.  The  Stapedius  emerges 
from  a  small  opening  in  the  posterior  wall  of  the  tympanic  cavity,  and  is 
inserted  into  the  neck  of  the  stapes.  It  is  supplied  by  the  facial  nerve  just 
before  it  reaches  the  stylo-mastoid  foramen.  In  paralysis  of  this  nerve, 
proximal  to  the  origin  of  the  branch  to  the  stapedius,  the  condition  of  hyper- 
acousis  occurs  as  a  result  of  paralysis  of  the  muscle. 

The  auditory  ossicles  and  the  tendons  of  their  muscles  are  all  covered  by 
the  mucous  membrane,  which  extends  backwards  from  the  naso-pharynx 
along  the  auditory  tube,  through  the  tympanic  cavity  and  aditus  into  the 
tympanic  antrum  and  its  furthest  ramifications. 

The  Tympanic  (Mastoid)  Antrum,  which  is  present  at 
birth,  is  relatively  larger  in  the  child  than  in  the  adult.  It  lies 
behind  and  slightly  above  the  tympanic  cavity,  with  which  it 
communicates  thiough  the  aditus.  Its  lateral  wall,  formed 
by  the  squamous  portion  of  the  temporal,  is  only  one-sixteenth 
of  an  inch  thick  at  birth,  but  by  the  ninth  year  it  has  increased 
to  nearly  half  an  inch.  The  floor  and  medial  wall,  formed  by 
the  petrous  portion  of  the  temporal,  separate  the  antrum  from 
the  posterior  cranial  fossa  and  the  descending  portion  of  the 
transverse  (lateral)  sinus,  which  forms  a  deep  groove  on  the  in- 
ternal surface  of  the  mastoid  portion  of  the  temporal  bone. 
The  aditus  is  placed  above  the  level  of  the  floor,  and  consequently 
can  only  act  as  an  overflow  when  the  antrum  contains  fluid. 
The  roof  is  formed  by  a  backward  continuation  of  the  tegmen 
tympani. 

As  the  mastoid  process  develops  at  the  end  of  the  second 
year  its  diploe  is  gradually  replaced  by  air-cells,  which  are 
derived  from  the  antrum  and  maintain  their  connection 
with  it,  either  directly  or  indirectly  through  neighbouring  cells. 
Occasionally  the  process  is  entirely  hollowed  out  by  air-cells,  the 
pneumatic  type,  or  it  may  be  practically  solid,  the  sclerosed 
type.  Various  intermediate  forms  occur.  The  cells  which  lie 


THE  AUDITORY  APPARATUS  215 

in  relation  to  the  posterior  wall  of  the  external  acoustic  meatus 
are  termed  the  "  border  cells,"  and  when  filled  with  pus  they 
may  rupture  into  the  meatus  and  discharge  through  it. 

Septic  infection  may  spread  from  the  tympanic  antrum 
(i)  directly,  by  necrosis  of  bone,  (2)  by  venous  thrombosis,  or 
(3)  by  the  lymph  vessels. 

Upward  Spread  of  Infection,  which  may  or  may  not  be 
accompanied  by  destruction  of  the  tegmen  tympani,  may  cause 
an  extra-dural  abscess  in  the  middle  cranial  fossa  or  an  abscess 
in  the  temporal  lobe  of  the  brain.  The  veins  which  ascend 
through  the  petro-squamous  suture  open  into  the  superior 
petrosal  sinus,  and  through  them  the  latter  may  become  the 
site  of  a  septic  thrombosis.  Downward  Spread  involves  the 
internal  jugular  vein  (p.  213). 

By  necrosis  of  the  lower  part  of  the  medial  wall  of  the  antrum 
pus  may  pass  downwards  and  medially,  and  reach  the  mastoid 
notch  (digastric  fossa) — Bezold's  mastoiditis.  It  then  passes 
downwards  along  the  styloid  process  and  the  muscles  attached 
to  it,  and  gives  rise  to  a  deep-seated  and  dangerous  form  of 
cervical  cellulitis.  Backward  Spread  involves  the  transverse 
(lateral)  sinus,  and  may  pass  along  the  cerebellar  veins,  producing 
a  cerebellar  abscess.  Forward  Spread  infects  the  "  border  cells," 
and  thence  the  pus  may  reach  the  external  acoustic  meatus, 
or  may  spread  laterally  and  produce  an  abscess  which  points  on 
the  surface  under  cover  of  the  auricle.  When  the  pus  reaches 
the  outer  surface  of  the  bone  it  strips  up  the  periosteum  and 
forms  a  subperiosteal  abscess.  This  accounts  for  the  dis- 
placement of  the  auricle  in  a  downward  and  forward  direction. 
Abscesses  in  connection  with  the  mastoid  lymph  glands  (p.  no) 
lie  superficial  to  the  periosteum,  and  although  they  may  displace 
the  auricle  forwards,  they  are  never  accompanied  by  downward 
displacement.  Necrosis  of  the  medial  wall  of  the  aditus  exposes 
the  facial  nerve,  and  infection  may  pass  along  its  sheath  to  the 
base  of  the  brain,  setting  up  a  suppurative  basal  meningitis. 

Tuberculous  disease  of  the  temporal  bone,  a  common  condition 
in  children,  may  spread  in  any  of  the  directions  which  have  just 
been  described.  In  this  case,  and  also  in  chronic  otitis  media, 
the  anterior  auricular  and  the  upper  anterior  group  of  the  deep 
cervical  lymph  glands  are  usually  enlarged. 

The  Surgical  Approach  to  the  Tympanic  Antrum  is 
made  through  a  curved  incision,  which  commences  a  quarter 
of  an  inch  above  the  upper  attachment  of  the  auricle  and  extends 

14  c 


216  THE  HEAD  AND  NECK 

downwards  behind  it  on  to  the  mastoid  process.  In  the  infant, 
prior  to  the  development  of  the  mastoid  process,  the  facial 
nerve  runs  serious  risks  of  injury  if  the  incision  is  carried  too 
far  forwards,  because  its  point  of  exit  from  the  skull,  the  stylo- 
mastoid  foramen,  is  situated  on  the  infero-lateral  aspect  (p.  210). 
The  incision  is  carried  down  to  the  bone,  and  the  periosteum  and 
soft  structures  of  the  flap  are  dissected  forwards  until  the 
osseous  part  of  the  external  acoustic  meatus  is  visible,  and  the 
suprameatal  spine  and  the  posterior  root  of  -the  zygomatic  pro- 
cess of  the  temporal  bone  are  recognised.  If  the  posterior  edge 
of  the  incision  is  elevated,  an  emissary  vein  is  exposed  emerging 
from  the  mastoid  foramen,  through  which  it  communicates  with 
the  transverse  sinus.  When  it  is  found  thrombosed,  the  sinus 
will  be  similarly  affected.  Pus  may  sometimes  be  seen  emerging 
from  the  mastoid  foramen,  and  its  presence  indicates  that  pus 
will  be  found  in  the  transverse  sinus  and  is  suggestive  of  a  sub- 
dural  abscess. 

In  chiselling  through  the  bone  to  reach  the  antrum,  care  must 
be  taken  not  to  do  so  too  high,  lest  the  middle  cranial  fossa  be 
opened,  or  too  far  posteriorly,  lest  the  transverse  (lateral)  sinus 
be  injured.  The  site  selected  lies  below  the  posterior  root  of 
the  zygomatic  process  and  immediately  behind  the  supra- 
meatal spine.  In  the  child,  however,  these  bony  prominences 
are  not  developed,  and  the  bone  lying  just  behind  the  postero- 
superior  quadrant  of  the  external  acoustic  meatus  is  the  best 
guide  (Stiles).  The  chisel  is  directed  medially,  downwards  and 
forwards,  i.e.  parallel  to  the  external  acoustic  meatus.  It  is 
advisable  to  bevel  down  the  edges  as  the  opening  is  deepened, 
and  if  the  transverse  sinus  lies  further  forwards  than  normally, 
its  bluish  wall  will  be  observed  and  can  be  protected.  As  a  rule 
the  sinus  lies  half  an  inch  behind  the  external  acoustic  meatus, 
but  its  position  is  subject  to  variation  (p.  225). 

As  soon  as  a  cavity  is  reached,  a  probe  is  inserted  and  directed 
forwards  in  search  of  the  aditus.  The  sensation  produced  as 
the  probe  slips  into  the  passage  is  unmistakable,  and  if  it  is  not 
experienced,  the  cavity,  which  is  only  an  air-cell,  is  deepened 
until  the  antrum  is  opened.  It  may  be  necessary  to  remove 
the  lateral  wall  of  the  aditus  in  order  to  throw  the  two  cavities — 
tympanic  cavity  and  antrum — into  one.  Before  this  is  carried 
out,  a  Stacke's  protector  is  passed  into  the  aditus  from  the 
antrum,  to  preserve  the  facial  nerve  and  the  lateral  semicircular 
canal  (p.  213)  from  injury  should  the  chisel  accidentally  slip 


THE  AUDITORY  APPARATUS  217 

during  the  operation.  Occasionally,  when  the  lateral  wall  of 
the  aditus  is  being  removed,  the  bone  breaks  away  owing  to  the 
weakness  caused  by  the  facial  canal  (aqueduct  of  Fallopius), 
and  a  short  piece  of  the  facial  nerve  is  exposed.  This  may  be 
bruised  during  the  remaining  steps  of  the  operation,  or  it  may 
be  pressed  upon  by  the  packing,  etc.,  leading  to  a  complete  but 
transitory  facial  paralysis.  Any  irritation  of  the  nerve  sets  up 
a  spasm  of  the  facial  muscles,  and  the  anaesthetist  is  able  to  warn 
the  surgeon.  When  the  antrum  and  tympanic  cavity  are 
syringed  out,  some  of  the  fluid  used  may  pass  along  the  auditory 

Lateral  semicircular  canal  Posterior  semicircular  canal 

Remains  of  posterior  .•    Temporal  line 

wall  of  external  meatus  /        ,  r 

Wall  of  groove  for 
sigmoid  part  of 
transverse  sinus 


Tympanic  plate  ' 

Styloid  process  '^         Wan  ?f  canalis 
facialis 

FIG.  66. — Dissection  of  the  Tympanic  (Mastoid)  Antrum  and  the  petro- 
mastoid  part  of  the  Temporal  Bone  from  the  outer  side.  The  arrow 
is  passing  through  the  aditus  from  the  tympanic  antrum  into  the 
tympanic  cavity. 

tube  into  the  nasal  pharynx,  and  the  anaesthetist  must  be  pre- 
pared to  prevent  it  from  passing  down  into  the  larynx. 

The  mucous  membrane  of  the  tympanic  cavity,  together 
with  the  incus  and  malleus,  may  require  to  be  removed ;  but 
the  stapes,  which  is  firmly  attached  to  the  fenestra  of  the  vesti- 
bule (fenestra  ovalis),  is  left  in  situ,  as  otherwise  the  internal 
ear  would  be  opened. 

After  the  antrum  has  been  dealt  with,  the  opening  may  be 
enlarged  upwards  and  forwards  to  explore  the  middle  cranial 
fossa  (p.  231),  or  backwards  to  explore  the  transverse  sinus 
and  cerebellum  (p.  216),  if  the  symptoms  point  to  a  spread  of  the 
disease  in  either  direction. 


2i8          THE  HEAD  AND  NECK 


THE  HEAD. 

Bony  Landmarks. — The  External  Occipital  Protuberance 
lies  just  above  a  small  depression,  which  indicates  the  upper  end 
of  the  nuchal  furrow  when  the  head  is  held  erect.  Two  inches 
above  it  in  the  median  line  the  Lambdoidal  Suture  can  be  recog- 
nised as  an  irregular  depression.  The  Parietal  Tuber  (Eminence), 
which  overlies  the  supra-marginal  convolution  of  the  brain,, 
can  be  felt  on  the  side  of  the  skull  about  two  inches  above  the 
auricle.  It  is  crossed  by  the  Superior  Temporal  Line  (Crest), 
which  can  be  traced  downwards  and  forwards  to  the  zygomatic 
(external  angular)  process  of  the  frontal  bone,  and  downwards 
and  backwards  to  a  point  a  little  above  and  behind  the  mastoid 
process.  The  Asterion,  which  corresponds  to  the  articulation 
of  the  mastoid  (postero-inferior)  angle  of  the  parietal  bone  with 
the  temporal,  forms  a  depression  above  and  behind  the  external 
acoustic  meatus.  It  lies  about  midway  between  the  Sylvian 
point  (p.  229)  and  the  external  occipital  protuberance.  Other 
bony  landmarks  have  been  dealt  with  on  pp.  170,  171. 

The  Skin  of  the  Scalp  contains  a  large  number  of  sebaceous 
glands,  and  is  therefore  a  common  site  for  sebaceous  cysts  or 
wens.  These  swellings  are  embedded  in  the  superficial  fascia, 
which  in  this  region  consists  of  a  dense  network  of  fibrous  tissue 
containing  very  small  lobules  of  fat.  They  can  be  moved  with 
the  scalp,  and  this  feature  distinguishes  them  from  tumours  in 
connection  with  the  pericranium. 

Numerous  arteries  supply  the  scalp,  ramifying  for  the  most 
part  in  the  subcutaneous  layer.  They  are  derived  from  both 
the  external  and  the  internal  carotid  arteries,  and  ascend  to- 
wards the  vertex  from  the  orbit,  face,  and  neck.  A  free  anasto- 
mosis occurs  between  the  two  groups  of  vessels  and  across  the 
median  line.  In  consequence,  ligature  of  one  external  carotid 
fails  to  cure  a  cirsoid  aneurism  of  the  superficial  temporal  artery. 
Subcutaneous  haemorrhage  is  limited  in  amount  owing  to  the 
density  of  the  tissue,  and  for  the  same  reason  superficial  septic 
infections  remain  localised  and  are  extremely  painful.  When 
one  of  these  vessels  is  cut  the  bleeding  is  plentiful,  as  its  wall 
is  held  open  and  prevented  from  retracting  by  its  attachment 
to  the  fibrous  septa.  At  the  same  time  the  density  of  the  sub- 
cutaneous tissue  renders  the  cut  vessels  difficult  to  catch,  but 
moderate  pressure  usually  suffices  to  stop  the  haemorrhage. 


THE  HEAD  219 

Owing  to  its  rich  blood-supply,  the  scalp  possesses  remarkable 
vitality.  Large  areas  may  be  stripped  up,  and  although  they 
may  only  remain  attached  by  narrow  pedicles,  if  replaced  they 
will  heal  with  little  loss  from  sloughing. 

Vessels  and  Nerves  of  the  Scalp.  —  The  Superficial  Temporal  Arteries 
supply  the  lateral  aspects  of  the  scalp  and  ascend  to  the  vertex  to  anasto- 
mose with  one  another.  They  divide  into  frontal  (anterior)  and  parietal 
(posterior)  branches,  which  communicate  freely  with  the  supra-orbital  and 
frontal  arteries  in  the  forehead  and  with  the  posterior  auricular  and  occipital 
arteries  behind  the  auricle.  The  superficial  temporal  artery  is  accompanied 
by  the  Auricula-  Temporal  Nerve. 

The  Supra-Orbital  and  Frontal  Arteries  accompany  the  Supra-Orbital  and 
Supra-Trochlear  Nerves  (Fig.  59).  They  are  branches  of  the  ophthalmic 
artery,  which  arises  from  the  internal  carotid. 

The  Posterior  Auricular  Artery  runs  backwards  and  upwards  from  the 
external  carotid,  and  lies  superficial  to  the  mastoid  process.  It  supplies  the 
auricle  and  adjoining  area  of  the  scalp,  and  is  accompanied  by  the  terminal 
branches  of  the  Great  Auricular  (p.  108)  and  the  Lesser  Occipital  Nerves 
(p.  108). 

The  Occipital  Artery  (p.  122)  supplies  the  back  of  the  scalp,  and  its  branches 
accompany  those  of  the  Greater  Occipital  Nerve  (p.  138). 

The   Galea  Aponeurotica   (Epicranial   Aponeurosis)  is    a 

thin  tendinous  sheet  which  unites  the  frontal  and  occipital  bellies 
of  the  epicranius  (occipito-frontalis)  to  one  another.  Unless 
it  is  cut  through  in  a  transverse  direction,  scalp  wounds  do  not 
tend  to  gape.  Its  lateral  margins  blend  with  the  strong  tem- 
poral fascia,  and,  together  with  the  line  of  origin  of  the  muscular 
bellies,  completely  shut  in  the  subaponeurotic  space  which  separ- 
ates the  galea  aponeurotica  from  the  pericranium.  This  space 
only  contains  some  loose  connective  tissue  and  a  few  small 
arteries,  but  it  is  traversed  by  the  important  emissary  veins 
which  connect  the  intra-cranial  venous  sinuses  and  the  superficial 
veins  of  the  scalp.  When  pus  collects  in  this  region  it  can  spread 
in  all  directions  so  as  to  elevate  the  scalp,  which  feels  to  the  ex- 
amining fingers  as  if  it  were  lying  on  a  water-bed.  Incisions  for 
the  evacuation  of  such  a  collection  are  made  near  its  lower 
border  and  parallel  to  the  larger  blood-vessels.  The  pus  may 
destroy  the  pericranium  and  cause  necrosis  of  the  bones  of  the 
skull ;  and  it  may  produce  septic  thrombosis  of  the  emissary 
veins,  and  emboli  may  spread  to  the  intra-cranial  sinuses.  On 
this  account  the  subaponeurotic  space  is  frequently  referred  to 
as  the  Dangerous  Area. 

The  Venous  Return  from  the  Scalp  may  pass  by  (i)  the 
extra-cranial  or  (2)  the  intra-cranial  route. 

I,  The  extra-cranial  route  is  constituted  by  the  veins  corre- 


220 


THE  HEAD  AND  NECK 


spending  to  the  branches  of  the  external  carotid  artery  which 
are  found  in  the  scalp,  and  by  the  supra-orbital  and  frontal 
veins  which  unite  to  form  the  angular  vein  (p.  175). 


FIG.  67.  — Diagrammatic  Representation  of  a  Frontal  Section  through  the 
Scalp,  Cranium,  Meninges,  and  Cortex  Cerebri  (modified  from  Cunningham). 

1.  Integument. 

2.  Artery  in  superficial  fascia. 

3.  Vein  in  superficial  fascia. 

4.  Diploic  vein,  connecting  veins  of  scalp 

with  veins  of  dura  mater. 

5.  Vein  in  dura  mater. 

6.  Arachnoid. 

7.  Pia  mater. 

8.  Arachnoidal  granulation. 

9.  Cortex  cerebri. 

TO.   Superior  sagittal  sinus. 

11.  Vein  in  pia  mater. 

12.  Sub-arachnoid  space. 


13.  Epicranial  aponeurosis. 

14.  Lax  connective  tissue. 

15.  Pericranium. 

16.  Outer  table  of  cranium. 

17.  Diploe. 

1 8.  Anastomosis  between  arteries  of  scalp 

and  those  of  dura  mater. 

19.  Inner  table  of  cranium. 

20.  Dura  mater. 

21.  Parasinoidal  sinus. 

22.  Cerebral   vein    opening    into    superior 

sagittal  sinus. 


2.  The  venous  blood  may  return  along  the  parietal  emissary 
vein  into  the  superior  sagittal  (longitudinal)  sinus,  or  along  the 
mastoid  and  condyloid  emissary  veins  into  the  transverse  (lateral) 
sinus.  Further,  the  supra  -  orbital  veins  communicate  with 


THE  HEAD  221 

the  ophthalmic  veins,  and  by  this  route  venous  blood  may  be 
returned  from  the  scalp  to  the  cavernous  sinus. 

In  addition  to  those  mentioned  above>  emissary  veins  con- 
nect the  superior  sagittal  (longitudinal)  sinus  with  the  veins  of 
the  nasal  mucous  membrane  through  the  foramen  caecum,  and 
the  cavernous  sinus  with  the  pterygoid  venous  plexus.  Epi- 
staxis  is  common  in  children  during  a  fit  of  violent  temper  or  of 
crying,  and  it  serves  to  reduce  the  intra-cranial  blood-pressure. 
In  this  way  the  emissary  veins  may  act  as  safety  valves. 

The  Pericranium  covers  the  outer  surface  of  the  skull  and  is 
easily  stripped  off  except  at  the  sutures,  where  it  is  connected 
with  the  endo-periosteal  layer  of  the  dura  mater.  The  latter 
provides  the  bones  of  the  skull  with  their  blood-supply,  and  on 
this  account  removal  of  portions  of  the  pericranium,  in  operations 
for  tuberculous  periostitis  of  the  skull,  is  not  necessarily  followed 
by  death  of  the  exposed  bone.  A  sub-pericranial  haemorrhage, 
or  cephal-hccmatoma,  is  limited  to  the  surface  of  some  particular 
bone  by  the  inter-sutural  membrane.  It  is  probably  due  to  the 
rupture  of  some  of  the  inter-sutural  veins  during  the  moulding 
of  the  fcetal  head,  and  can  easily  be  distinguished  from  the 
swelling  produced  by  Caput  Succedaneum,  as  the  latter  occurs  in 
the  scalp  and  is  not  limited  to  the  surface  of  any  particular  bone. 

The  Developing  Cranium  expands  rapidly  to  accommodate 
itself  to  the  rapidly  growing  brain.  At  first  it  consists  of  a 
membranous  capsule,  but  supporting  cartilaginous  bars  soon 
appear  in  its  base.  The  bars  become  ossified,  and  at  the  same 
time  centres  of  ossification  appear  in  the  membrane  to  form  the 
parietal  bone  and  the  squamous  portions  of  the  temporal, 
occipital,  and  frontal  bones.  In  the  regions  of  the  anterior  and 
posterior  fontanelles  the  membrane  is  the  only  covering  of  the 
brain  and  its  meninges  at  birth.  The  anterior  fontanelle  is 
placed  at  the  area  where,  in  the  adult,  the  coronal  and  sagittal 
sutures  meet,  and  through  it  the  pulsations  of  the  brain  can 
readily  be  seen  and  felt.  It  should  be  closed  by  the  end  of  the 
second  year,  but  in  rickets  it  is  still  widely  open  at  that  age. 
When  the  intra-cranial  pressure  is  raised,  e.g.  in  crying,  the 
anterior  fontanelle  becomes  tense,  while  it  is  sunken  in  con- 
ditions of  malnutrition  and  exhaustion.  Faulty  development 
of  the  skull  at  the  suture  lines  is  accountable  for  the  various 
forms  of  meningoceles  (p.  534). 

The  cranial  deformities  produced  by  hydrocephalus  (p.  226) 
are  determined  by  the  condition  of  the  sutures  at  the  time  of 


222  THE  HEAD  AND  NECK 

the  onset  of  the  disease.  If  it  occurs  after  the  closure  of  the 
sagittal  suture,  the  frontal  and  occipital  regions  are  both  affected, 
but  if  the  lambdoidal  suture  is  also  closed  the  bulging  is  confined 
to  the  region  of  the  forehead. 

Fracture  of  the  Skull. — In  relation  to  cranial  injuries 
haemorrhage  alone  is  of  very  little  diagnostic  value,  but  the 
accompanying  or  subsequent  discharge  of  cerebro-spinal  or 
subdural  fluid  is  positive  evidence  of  a  fracture  of  the  skull. 

Anterior  Fossa. — Fracture  of  the  lamina  cribrosa  of  the 
ethmoid  bone  is  usually  accompanied  by  laceration  of  the  mucous 
membrane  of  the  roof  of  the  nose.  This  injury,  therefore, 
gives  rise  to  epistaxis,  accompanied  or  followed  by  a  discharge 
of  cerebro-spinal  fluid.  In  addition,  there  is  frequently  some 
loss  of  smell  due  to  laceration  of  the  olfactory  nerves  as  they 
pass  upwards  from  the  nose.  In  fracture  of  the  orbital  part 
(plate)  of  the  frontal  bone,  sub-conjunctival  ecchymosis  is  a 
characteristic  feature,  and  the  haemorrhage  within  the  orbit 
may  produce  exophthalmos.  When  the  frontal  air  sinus  is 
also  injured,  blood  may  pass  down  the  infundibulum  to  the  middle 
meatus  and  be  discharged  from  the  nose.  In  these  cases  the 
haemorrhage  arises  from  the  torn  branches  of  the  anterior 
division  of  the  middle  meningeal  artery  or,  more  rarely,  from 
the  ophthalmic  vessels.  Some  of  the  blood  may  be  swallowed, 
giving  rise  subsequently  to  hsematemesis. 

Middle  Fossa. — This  is  the  commonest  site  of  fracture  of  the 
skull,  partly  because  of  its  position  but  also  because  it  is  weak- 
ened by  numerous  canals  and  foramina.  The  tegmen  tympani 
(p.  212)  is  usually  fractured,  and  the  tympanic  membrane  is 
torn.  Blood  and  cerebro-spinal  fluid  are  discharged  from  the 
external  acoustic  meatus,  and  the  facial  and  auditory  (seventh 
and  eighth  cerebral)  nerves  may  be  involved  (p.  213).  Some- 
times the  walls  of  the  cavernous  sinus  are  lacerated,  and  some 
of  the  nerves  (third,  fourth,  and  sixth  cerebral)  which  lie  in  its 
lateral  wall  are  paralysed  (p.  225). 

Posterior  Fossa. — In  this  case  the  haemorrhage  does  not 
become  evident  at  once,  unless  the  basilar  part  of  the  occipital 
bone  is  fractured,  with  laceration  of  the  mucous  membrane  of 
the  pharyngeal  roof.  Otherwise  the  blood  is  situated  deeply 
at  the  back  of  the  neck,  and  the  discoloration  does  not  become 
apparent  for  some  days.  It  reaches  the  surface  in  the  posterior 
triangle  or  in  the  neighbourhood  of  the  mastoid  process. 


THE  BRAIN  AND  ITS  MENINGES  223 


THE  BRAIN  AND   ITS  MENINGES. 

The  Dura  Mater  is  a  fibro-serous  membrane.  The  fibrous 
layer  forms  the  endo-periosteum  of  the  skull,  to  which  it  is 
attached  by  numerous  fibrous  processes,  but  it  is  only  strongly 
adherent  over  the  floor  of  the  cranial  fossae  and  along  the  suture 
lines.  The  meningeal  vessels  lie  between  the  dura  mater  and 
the  bone,  and,  owing  to  the  ease  with  which  the  membrane 
may  be  stripped  off,  extra-dural  blood-clots  may  attain  a  suffi- 
ciently large  size  to  exert  a  fatal  degree  of  intra-cranial  pressure. 
The  serous  layer  forms  a  covering  for  the  brain  and  supports  the 
thin  endothelial  walls  of  the  cranial  blood  sinuses,  which,  conse- 
quently, do  not  collapse  when  they  are  wounded.  The  falx 
cerebri  is  a  fold  of  the  serous  layer,  which  passes  downwards  in 
the  middle  line  between  the  two  cerebral  hemispheres.  Pos- 
teriorly, a  similar  fold,  termed  the  tentorium  cerebelli,  projects 
inwards  between  the  cerebellum  and  the  cerebrum ;  and  the 
two  cerebellar  hemispheres  are  partially  separated  by  the  falx 
cerebelli,  a  small  fold  which  extends  from  the  internal  occipital 
protuberance  to  the  posterior  border  of  the  foramen  magnum. 

The  Superior  Sagittal  (Longitudinal)  Sinus  lies  in  the 
upper  margin  of  the  falx  cerebri  (Fig.  68).  It  begins  at  the  fora- 
men caecum,  where  it  communicates  with  the  nasal  veins  (p. 
221),  and  runs  backwards  to  the  internal  occipital  protuberance. 
At  this  point  it  communicates  with  the  straight  sinus,  and  turns 
laterally,  usually  to  the  right,  to  form  the  transverse  sinus. 
It  is  half  an  inch  in  breadth  posteriorly,  and,  therefore,  trephine 
openings  should  not  be  made  less  than  three-quarters  of  an  inch 
from  the  median  line.  In  addition  to  the  parietal  emissary  vein 
(p.  220),  it  receives  numerous  cerebral  veins,  which  run  forwards 
and  medially  to  enter  the  sinus.  Backward  movements  of  the 
head,  which  tend  to  empty  the  sinus,  retard  the  outflow  from 
the  cerebral  veins,  owing  to  their  forward  inclination. 

The  Inferior  Sagittal  Sinus  lies  in  the  lower  border  of  the 
falx  cerebri,  and  is  joined  posteriorly  by  the  great  cerebral 
vein  (of  Galen)  to  form  the  Straight  Sinus,  which  runs  back- 
wards on  the  upper  surface  of  the  tentorium  cerebelli  and  in  the 
base  of  the  falx  cerebri.  At  the  internal  occipital  protuberance 
the  straight  sinus  bends  laterally  to  form  the  transverse  sinus, 
usually  of  the  left  side,  but  at  its  termination  it  communicates 
freely  with  the  superior  sagittal  sinus. 


224 


THE  HEAD  AND  NECK 


The  Transverse  Sinus  runs  laterally  and  slightly  upwards 
from  the  internal  occipital  protuberance;  grooving  the  occipital 
bone.  Its  highest  point  is  placed  on  the  mastoid  (postero- 
inferior)  angle  of  the  parietal  bone,,  and  it  then  turns  downwards,, 
forming  a  deep  groove  on  the  mastoid  portion  of  the  temporal 
bone.  Its  horizontal  part  lies  in  the  attached  margin  of  the 
tentorium  cerebelll.(Fig.  68) ,  but  its  vertical  portion  lies  in  the 
lateral  wall  of  the! posterior  cranial  fossa  and  is  situated  behind 
the  tympanic .  (mastoid)  antrum  (p.  214).  At  its  termination 
it  runs  medially  and  then  forwards  to  reach  the  jugular 
foramen,  through  which  it  passes  to  become  continuous  with 


Superior  sagittal  sinus 
Fossae  for  occipital  lobes 


Falx  cerebri 


Straight  sinus 


Transverse'sinus 


Fossae  for  cerebellum 


Transverse  sinus 


Occipital  sinus 


FIG.  68. — Oblique  Section  through  Posterior  part  of  Skull,  showing  the 
relationship  of  the  Dura  Mater  to  the  Cerebral  Sinuses.  The  fibrous 
layer  of  the  dura  mater  is  shown  in  blue,  and  the  serous  layer  in  red. 

the  internal  jugular  vein.  It  receives  the  mastoid  emissary  vein 
(p.  216)  and  tributaries  from  the  cerebellum  and  the  lower  part 
of  the  lateral  surface  of  the  cerebrum. 

The  transverse  sinus  corresponds  roughly  to  the  superior 
nuchal  (curved)  line  on  the  occipital  bone.  In  mapping  it  out 
on  the  surface  it  must  be  borne  in  mind  that  the  sinus  is  about 
one-third  of  an  inch  wide.  It  commences  a  little  above  the 
external  occipital  protuberance  and  runs  laterally  to  the  asterion 
(p.  218).  In  this  part  of  its  course  the  sinus  presents  a  varying 
degree  of  upward  convexity,  but  the  summit  of  its  curve  is 
rarely  higher  than  a  point  one  ringer's  breadth  above  the  middle 
of  the  line  joining  the  external  occipital  protuberance  to  the 
centre  of  the  external  acoustic  (auditory)  meatus.  The  descend- 


THE  BRAIN  AND  ITS  MENINGES  225 

ing  part  of  the  sinus  runs  downwards  and  slightly  forwards  to 
a  point  three-quarters  of  an  inch  below  and  behind  the  centre 
of  the  meatus.  Very  often,  however,  it  approaches  nearer  to 
the  meatus,  and  in  this  event  it  may  be  exposed  during  opera- 
tions on  the  tympanic  (mastoid)  antrum. 

The  Cavernous  Sinuses  lie  one  on  each  side  of  the  body 
of  the  sphenoid  and  are  separated  by  the  hypophysis  (pituitary 
body),  but  they  communicate  freely  with  one  another.  An- 
teriorly, the  cavernous  sinus  receives  the  ophthalmic  veins, 
and  posteriorly  the  blood  is  drained  into  the  transverse  sinus 
by  the  superior  petrosal,  and  into  the  commencement  of  the 
internal  jugular  vein  by  the  inferior  petrosal  sinus.  The  cavern- 
ous sinus  communicates  with  the  pterygoid  venous  plexus 
through  the  foramen  ovale  and  the  foramen  of  Vesalius.  Be- 
tween the  endothelial  wall  of  the  sinus  and  the  serous  layer  cf 
the  dura  mater  which  supports  it  laterally,  the  third,  fourth, 
and  sixth  cerebral  nerves  and  the  ophthalmic  division  of  the  fifth 
pass  forwards  to  the  orbit  (p.  207),  and  a  similar  position  is 
occupied  by  the  internal  carotid  artery.  Any  or  all  of  these 
structures  may  be  involved  by  (i)  tumours  of  the  hypophysis 
(pituitary  body)  which  extend  in  a  lateral  direction,  (2)  throm- 
bosis of  the  sinus,  (3)  fractures  of  the  skull  in  this  region. 

The  Occipital  Sinus  (p.  227)  lies  in  the  attached  border 
of  the  falx  cerebelli,  and  runs  upwards  to  join  the  right  or  left 
transverse  sinus  near  its  commencement. 

The  Arachnoid  and  the  Pia  Mater  are  two  membranes 
which  are  applied  to  the  surface  of  the  brain  more  closely  than 
the  dura  mater.  The  pia  mater  dips  into  all  the  fissures,  but  the 
arachnoid  only  does  so  in  the  case  of  the  longitudinal  fissure 
and  the  lateral  fissure  (of  Sylvius).  In  certain  areas  the  two 
membranes  are  separated  by  the  subarachnoid  cisterns.  Of 
these  the  most  important  are  situated  on  the  basal  surface 
of  the  brain,  and  in  basal  meningitis  they  become  filled  with 
purulent  exudates,  which  may  press  on  the  neighbouring 
cerebral  nerves  (second  to  the  eighth  inclusive). 

The  Ventricular  System  of  the  Brain  and  Spinal 
Medulla. — The  central  canal  is  a  small  channel  which  extends 
upwards  through  the  whole  length  of  the  spinal  medulla  into 
the  medulla  oblongata,  where  it  expands  to  form  the  fourth 
ventricle.  From  the  upper  part  of  the  fourth  ventricle  the 
cerebral  aqueduct  (of  Sylvius}  passes  through  the  mid-brain  to 
open  into  the  third  ventricle,  which  in  its  turn  communicates 

15 


226 


THE  HEAD  AND  NECK 


with  the  lateral  ventricles  through  the  inter-ventricular  foramina 
of  Monro.  The  whole  of  this  system  is  lined  by  ependyma,  a 
thin  membrane  covered  by  ciliated  columnar  epithelium. 
The  cerebro- spinal  fluid  fills  the  ventricular  system,  and  normally 
drains  away  through  certain  apertures  in  the  walls  of  the 
ventricles  into  the  subarachnoid  space.  The  largest  of  these 
apertures  (the  foramen  of  Magendie)  is  placed  in  the  lower 


Higher  motor  centres  for  lower  limb 

Central  sulcus 
Cerebral  aqueduct 


Higher 
visual  centres 


Sulcus  cinguli 

|  Corpus  callosum 

Interventricular  foramen 
(of  Monro) 


cut 

ophysis 

Cisterna  interpeduncularis 
Midbrain 
s 

edian  aperture  of  fourth  ventricle 
(foramen  of  Magendie) 
Medulla  oblongata 

x'Cisterna  cerebello-medullaris 
""-,  Central  canal  of  spinal  medulla 

FIG.  69. — Median  Section  through  the  Brain.     The  arachnoid 
is  shown  in  blue. 


Fourth  ventricle 


part  of  the  roof  of  the  fourth  ventricle.  The  cerebro-spinal 
fluid  passes  through  the  arachnoid  by  a  process  of  osmosis  into 
the  sub-dural  space,  where  it  mixes  with  the  sub-dural  fluid 
and  ultimately  becomes  absorbed.  It  is  derived  from  the 
veins  of  the  chorioid  plexus,  which  invaginate  the  ependyma 
and  project  into  the  cavities  of  the  lateral  and  fourth 
ventricles. 

Congenital  Hydrocephalus  is  said  to  be  due  (i)  to  an  in- 
crease in  the  amount  of  cerebro-spinal  fluid  secreted  or  (2)  to 
a  diminished  rate  of  absorption.  On  the  ground  of  the  former 


THE  BRAIN  AND  ITS  MENINGES  227 

theory  Stiles  treats  the  condition  by  ligature  of  the  common 
carotid  arteries  (p.  119). 

Acquired  Hydrocephalus  may  be  caused  by  obstruction  to 
the  outflow  into  the  subarachnoid  space  (p.  226)  by  adhesions  fol- 
lowing meningitis,  or  it  may  be  produced  by  pressure  on  the  great 
cerebral  vein  (of  Galen).  In  the  latter  case  the  veins  of  the 
choroid  plexus  become  conges  ted,  and  increased  transudation 
takes  place  through  the  ependyma  into  the  interior  of  the  ven- 
tricles. In  the  former  case  the  condition  may  be  cured  by  mak- 
ing a  fresh  opening  in  the  roof  of  the  fourth  ventricle  so  as  to 
re-establish  the  communication  between  the  ventricular  system 
and  the  subarachnoid  space.  In  this  operation  an  anchor- 
shaped  incision  is  employed.  The  curved  base  of  the  anchor 
lies  along  the  superior  nuchal  (curved)  lines  of  the  occipital  bone, 
and  from  its  centre  a  vertical  incision  passes  downwards  along 
the  ligamentum  nuchae.  The  knife  is  carried  down  to  the  bone 
and  the  two  flaps  are  reflected  downwards  and  laterally.  The 
skull  is  opened  below  the  level  of  the  transverse  sinus  (p.  224) 
and  at  the  thinnest  part  of  the  occipital  bone,  to  one  side  of  the 
median  line.  The  opening  is  enlarged  by  removing  the  lower 
portion  of  the  squamous  part  of  the  occipital  bone  piecemeal, 
including  the  posterior  margin  of  the  foramen  magnum  as  far 
forwards  as  the  posterior  edges  of  the  condyles.  During  the 
process  considerable  oozing  occurs  from  injured  diploic  veins. 
The  occipital  sinus  is  ligatured  above  and  below,  and  the  dura 
mater  is  then  opened  along  one  side  of  the  sinus.  Horizontal 
incisions  are  made  at  each  end  of  this  cut,  and  two  flaps  of  dura 
mater,  one  of  which  contains  the  ligated  portion  of  the  occipital 
sinus,  are  turned  laterally.  This  step  exposes  the  postero- 
inferior  aspect  of  the  cerebellum,  covered  by  the  arachnoid  and 
the  pia  mater.  The  cerebellum  is  pressed  upwards,  away  from 
the  posterior  aspect  of  the  medulla  oblongata  (Fig.  69),  and  a 
large  subarachnoid  cistern  (cerebello- medullary)  is  brought 
into  view.  After  the  cistern  is  opened,  the  lower  part  of  the 
bulging  roof  of  the  fourth  ventricle,  which  consists  of  ependyma 
and  pia  mater,  is  exposed,  and  the  communication  between  the 
ventricular  system  and  the  subarachnoid  space  may  be  re- 
established. 

The  operation  of  suboccipital  decompression,  as  practised  by 
Gushing,  follows  the  same  course  as  far  as  the  incision  of  the 
dura  mater. 

In  evacuating  a  cerebellar  abscess  the  same  route  is  adopted. 

15  a 


228 


THE  HEAD  AND  NECK 


After  the  membranes  have  been  opened,  a  director  is  passed 
into  the  substance  of  the  cerebellum  at  the  point  where  the 
bulging  is  greatest.  The  instrument  must  not  be  passed  in 


70.  — Cranio-Cerebral  Topography.     The  figure  shows  the  positions  of 
the  motor  and  sensory  areas  and  their  relations  to  Chiene's  lines. 


G. 
O. 
M. 
T. 
S. 
E. 
P. 
N. 
R. 
C. 


Glabella. 

External  occipital  protuberance. 
Mid-point  between  G  and  O. 
Mid-point  between  M  and  O. 
Mid-point  between  T  and  O. 
Zygomatic  process  of  frontal. 
Pre-auricular  point. 
Mid-point  of  EP. 
Mid-point  of  PS. 
Mid-point  of  AB. 


CD    is  drawn  parallel  to  AM. 


Z.        Post-auricular  point. 

VW.  Guide  to  anterior  limit  of  transverse 

sinus. 

Y.       Tympanic  antrum. 
X1.     Site  nt  which  sub  -  arachnoid  space 

may  be  opened. 
X2.      Site    for   draining    lateral    ventricle 

(Kocher). 
X3.      Site    for    draining    lateral    ventricle 

(Keen). 


for  more  than  i  J  inches,  and  it  may  be  withdrawn  and  reinserted 
in  different  directions  till  the  pus  is  found. 

The  Lateral  Surface  of  the  Cerebral  Hemisphere.— 
The  Central  Sulcus  (of  Eolando)  crosses  this  surface  of  the 


THE  BRAIN  AND  ITS  MENINGES  229 

brain  obliquely  and  separates  the  frontal  from  the  parietal 
lobe.  It  begins  at  the  supero-median  border  and  runs  down- 
wards, forwards,  and  laterally  to  end  a  little  above  the  posterior 
ramus  of  the  lateral  fissure  (of  Sylvius).  The  Anterior  and 
Posterior  Central  (Pre-  and  Post-Central)  Gyri  are  two  parallel 
and  nearly  vertical  convolutions,  which  lie  one  on  each  side  of 
the  central  sulcus.  The  motor  area  is  situated  in  the  grey  matter 
of  the  anterior  central  gyrus  and  in  the  anterior  wall  of  the 
central  sulcus  (of  Rolando),  but  it  does  not  extend  on  to  the 
surface  of  the  posterior  central  gyrus.  In  front  of  the  lower  end 
of  the  sulcus,  the  motor  centre  for  the  face  is  situated,  and  above 
lie  the  centres  for  the  neck,  upper  limb,  trunk,  and  lower 
limb,  in  that  order.  The  last-named  extends  from  the  supero- 
median  border  on  to  the  upper  part  of  the  medial  surface  of  the 
hemisphere  (Fig.  69). 

The  upper  end  of  the  central  sulcus  (of  Rolando)  corresponds 
to  a  point  half  an  inch  behind  the  mid-point  of  the  line  joining 
the  nasion  to  the  external  occipital  protuberance.  The  sulcus 
itself  can  be  mapped  out  by  drawing  a  line,  inclined  at  an  angle 
of  67!°  to  the  sagittal  suture,  downwards  and  forwards  from 
this  point  for  3!  inches.  The  direction  of  this  line  can  be  in- 
dicated on  the  head  by  placing  the  palm  upon  the  scalp  with  the 
index-finger  along  the  median  line  and  the  thumb  extended  so 
as  to  point  just  behind  the  apex  of  the  chin.  When  the  apex 
of  the  angle  between  the  thumb  and  the  index-finger  corresponds 
to  the  commencement  of  the  sulcus,  the  thumb  itself  indicates 
the  situation  of  the  sulcus  on  the  surface.  The  motor  area 
extends  forwards  for  half  an  inch  in  front  of  this  line.  It  is 
crossed  by  the  superior  temporal  line  at  or  near  the  lower  part 
of  the  upper  limb  centre,  and,  therefore,  that  part  of  the  skull 
which  overlies  the  face  centre  is  itself  covered  by  the  temporal 
muscle  and  fascia.  In  the  child,  owing  to  the  smaller  size  of 
the  muscle,  the  temporal  lines  lie  entirely  below  the  level  of  the 
motor  area. 

The  Lateral  Fissure  of  Sylvius  breaks  up  into  three  rami  as  soon  as  it 
appears  on  the  lateral  surface  of  the  brain.  The  point  at  which  this  takes 
place  lies  ij  inches  vertically  above  the  mid-point  of  the  zygomatic  arch.  It 
is  known  as  the  Sylvian  point  and  is  situated  opposite  the  Pterion,  the  region 
where  the  great  wing  of  the  sphenoid  articulates  with  the  sphenoidal  (antero- 
inferior)  angle  of  the  parietal  bone.  The  anterior  horizontal  and  anterior 
ascending  rami  extend  on  to  the  inferior  frontal  gyrus,  and  the  convolutions 
which  surround  them  are  known  as  Broca's  Area.  This  area  is  said  to  contain 
the  motor  speech  centre,  which  is  only  developed  on  the  left  side  of  the  brain. 
It  lies  immediately  above  the  Sylvian  point. 

156 


230  THE  HEAD  AND  NECK 

The  Posterior  Ramus  of  the  lateral  fissure  of  Sylvius  runs  backwards, 
forming  the  upper  boundary  of  the  temporal  lobe  ;  and,  posteriorly,  it  turns 
upwards  into  the  parietal  lobe.  It  may  be  mapped  out  on  the  surface  by 
drawing  a  line  from  the  Sylvian  point  backwards  for  three  inches  in  the 
direction  of  the  lambdoidal  suture  and  then  upwards  for  one  inch.  At  its 
termination  the  ramus  lies  under  cover  of  the  parietal  tuber  (eminence),  and 
is  surrounded  by  the  supra-marginal  convolution.  The  word-hearing  centre 
is  placed  in  the  superior  temporal  gyms,  below  the  middle  part  of  the  pos- 
terior ramus.  Immediately  behind  the  supra-marginal  convolution  lies  the 
angular  gyrus,  which  contains  the  word-seeing  centre.  It  can  be  exposed  by 
trephining  the  skull  a  little  below  and  behind  the  parietal  tuber. 

The  occipital  lobe  is  covered  by  the  upper  part  of  the  squamous  portion 
of  the  occipital  bone.  It  contains  the  higher  visual  centres,  but  they  are 
situated  chiefly  on  its  medial  surface. 

The  Middle  Meningeal  Artery  (p.  181)  enters  the  skull 
through  the  foramen  spinosum,  and  runs  laterally  and  slightly 
forwards  over  the  floor  of  the  middle  cranial  fossa  between  the 
dura  mater  and  the  bone.  One  finger's  breadth  above  the  mid- 
point of  the  zygomatic  arch,  it  divides  into  anterior  and  posterior 
branches.  The  former  runs  upwards  and  crosses  the  deep  sur- 
face of  the  pterion  opposite  the  Sylvian  point,  and  is  then  con- 
tinued upwards  along  the  anterior  border  of  the  motor  area. 
The  posterior  branch  runs  backwards  parallel  to  the  posterior 
ramus  of  the  lateral  fissure  of  Sylvius  and  about  three-quarters 
of  an  inch  above  the  level  of  the  zygomatic  arch. 

Surgical  Approach  to  the  Middle  Cranial  Fossa.— 
The  middle  cranial  fossa  is  opened  in  operations  in  connection 
with  the  semilunar  (Gasserian)  ganglion,  in  ligature  of  the 
branches  or  main  trunk  of  the  middle  meningeal  artery,  and  in 
subtemporal  decompression.  The  approach  is  very  much  the 
same  in  each  case.  The  incision  divides  the  skin  and  superficial 
fascia  from  the  zygomatic  (external  angular)  process  of  the 
frontal  bone  along  the  superior  temporal  line,  and  descends 
posteriorly  to  a  point  in  front,  above,  or  behind  the  auricle,  as 
the  case  may  be.  In  this  way  the  upper  branches  of  the  facial 
nerve,  which  lie  parallel  to  and  a  little  below  the  base  of  the 
flap,  are  preserved  intact.  The  flap  thus  mapped  out  is  turned 
downwards  till  the  zygomatic  arch  is  reached.  The  skull  may 
be  exposed  by  turning  down  a  flap,  consisting  of  the  temporal 
fascia  and  muscle,  or  the  fascia  alone  may  be  dissected  down- 
wards and  the  muscle  may  be  split  and  each  half  retracted 
(Cushing's  intermusculo-temporal  method  in  ligature  of  the 
anterior  division  of  the  middle  meningeal  artery). 

The  point  of  application  of  the  trephine  varies  with  the 
individual  operation.  After  a  circular  disc  of  bone  has  been 


THE  BRAIN  AND  ITS  MENINGES  231 

removed  the  opening  is  enlarged  by  means  of  craniectomy 
forceps.  The  inner  blade  of  this  instrument  is  blunt,  and 
formed  so  as  to  separate  the  dura  mater  from  the  inner  surface 
of  the  skull  while  the  bone  is  being  removed. 

(a)  In  Ligature  of  the  Anterior  Division  or  of  the  Main 
Trunk  of  the  Middle  Meningeal  Artery  the  trephine  is  applied 
over  the  Sylvian  point  (p.  229),  and,  when  the  disc  of  bone  is 
removed,,  the  anterior  division  is  exposed  running  upwards  over 
the  dura  mater.    Not  infrequently  the  artery  lies  in  a  small 
canal  on  the  deep  surface  of  the  bone,  and  in  these  cases  a  seg- 
ment of  the  vessel  will  be  removed  along  with  the  disc  of  bone. 
The  opening  must  then  be  enlarged  in  a  downward  direction 
until  the  vessel  is  found  leaving  the  canal,  when  its  proximal 
end  can  be  ligated. 

(b)  The  operation  of  Temporal  Decompression  is  undertaken 
to  relieve  the  symptoms  of  headache  and  progressive  loss  of 
vision,  which  result  from  increased  intra-cranial  pressure  due 
to  cerebral  tumours.    The  trephine  is  applied  behind  the  Sylvian 
point  in  order  to  avoid  the  anterior  branch  of  the  middle  menin- 
geal   artery.    The   opening  is   enlarged   in   a   downward   and 
backward  direction  till  its  diameter  has  been  increased  to  from 
2\  to  3  inches.    While  this  enlargement  is  being  carried  out 
the  posterior  division  of  the  middle  meningeal  artery  is  exposed. 
A  crucial  incision  is  made  in  the  bulging  dura  mater  after  all 
the  vessels  which  are  likely  to  be  cut  have  been  secured. 

(c)  The  approach  to  the  Semilunar  (Gasserian)  Ganglion  is 
described  on  p.  234. 

(d)  In  order  to  evacuate  an  Abscess  of  the  Temporal  Lobe 
a  trephine  opening  is  made  at  a  point  two  inches  above  the  ex- 
ternal acoustic  meatus.    The  skin  incision  begins  in  front  of  the 
auricle,  and  is  carried  upwards  and  backwards  above  it  and  then 
downwards  behind  it.     After  the  membranes  have  been  opened, 
a  director  is  passed  medially  into  the  brain  at  the  point  where 
it  bulges  most.     If  the  abscess  is  not  located  the  director  is 
withdrawn,  and  then  passed  forwards  and  medially  or  back- 
wards and  medially  until  pus  is  found.     Throughout  the  ex- 
ploration the  instrument  should  be  kept  parallel  to  the  tegmen 
tympani,  and  it  must  not  be  inserted  for  more  than  i£  inches 
lest  the  inferior  (descending)  horn  of  the  lateral  ventricle  be 
entered.    When  Horsley's  pus  evacuator  is  used  in  place  of  a 
director,  it  must  be  passed  in  closed,  and  it  should  be  opened  at 
intervals  of  a  quarter  of  an  inch.     In  order  to  prevent  severe 


232  THE  HEAD  AND  NECK 

laceration  of  the  brain,  the  instrument  must  be  kept  closed  while 
it  is  being  inserted  and  withdrawn. 

(e)  In  Ligature  of  the  Posterior  Division  of  the  Middle 
Meningeal  Artery  the  skull  is  trephined  at  a  point  one  inch  above 
and  behind  the  external  acoustic  meatus.  The  skin  incision  is 
planned  so  as  to  give  good  exposure  of  the  area. 

The  Approach  to  the  Anterior  Cranial  Fossa  may  be 
made  from  in  front  or  from  the  side.  In  the  latter  case  the 
approach  resembles  that  to  the  middle  fossa,  but  the  trephine 
is  applied  farther  forwards  and  sufficiently  high  to  preclude 
the  possibility  of  opening  through  the  lateral  wall  of  the  orbit. 

The  operation  is  generally  performed  for  abscess  of  the 
frontal  lobe,  and  it  may  be  difficult  to  determine  whether  the 
right  or  left  side  is  involved.  On  this  account  the  anterior  route 
may  be  preferred,  as  it  enables  the  surgeon  to  expose  the  frontal 
bone  on  both  sides  of  the  median  line.  The  incision  extends 
from  a  little  above  the  zygomatic  (external  angular)  process  of 
the  frontal  bone  on  one  side  to  a  corresponding  point  on  the 
opposite  side,  and  passes  chiefly  through  the  skin  of  the  anterior 
part  of  the  scalp.  In  this  way  subsequent  deformity  due  to 
scarring  may  be  avoided,  and  a  large  flap  may  be  turned  down- 
wards. The  trephine  must  be  applied  ij  inches  above  the 
superior  margin  of  the  orbit  so  as  to  avoid  opening  the  frontal 
air  sinus.  The  subsequent  procedure  is  very  similar  to  that 
described  for  the  evacuation  of  an  abscess  in  the  temporal  lobe. 

During  the  moulding  of  the  fatal  head  at  birth,  the  parietal 
bones  may  overlap  one  another  to  such  an  extent  as  to  cause 
rupture  of  the  superficial  cerebral  veins  near  their  union  with 
the  superior  sagittal  sinus.  The  subdural  haemorrhage  which 
ensues  is  usually  localised  to  the  motor  centre  for  the  lower 
limb  (p.  229),  and  it  gives  rise  to  an  irritative  condition  of  the 
cortex  and  to  symptoms  of  cerebral  compression.  Unless  these 
signs  are  recognised  and  operation  resorted  to  within  ten  days 
or  a  fortnight,  irreparable  damage  may  be  done  to  the  brain. 
Neglected  cases  of  this  kind  give  rise  to  one  of  the  varieties  of 
"  birth  palsy  " — Little's  disease.  The  haemorrhage  may  be 
confined  to  one  side  only  or  it  may  be  bilateral. 

A  curved  incision,  which  is  carried  down  to  the  bone,  is 
made  over  the  area  and  the  flap  is  turned  down.  The  thin 
superior  border  of  the  parietal  bone  is  exposed  and  a  blunt 
dissector  is  passed  under  it.  An  osseous  flap,  similar  in  shape 
to  but  slightly  smaller  than  the  flap  of  soft  parts,  is  made  with 


THE  BRAIN  AND  ITS  MENINGES  233 

scissors  and  the  bone  is  broken  across  its  base.  A  similar  flap 
of  the  dura  mater  is  turned  down,  and  the  clot  can  then  be 
removed. 

The  Trigeminal  or  Fifth  Cerebral  Nerve  possesses 
a  large  (sensory)  and  a  small  (motor)  root,  both  of  which  pierce 
the  serous  layer  of  the  dura  mater  near  the  apex  of  the  petrous 
portion  of  the  temporal  bone.  The  Semilunar  (Gasserian) 
Ganglion,  which  is  situated  on  the  large  (sensory)  root  as  it  lies 
on  the  petrous  temporal,  is  enclosed  between  the  serous  and 
fibrous  layers  of  the  dura  mater.  The  Ophthalmic,  Maxillary, 
and  Mandibular  nerves  arise  from  the  anterior  border  of  the 
ganglion. 

1.  The  Ophthalmic  Nerve  at  once  enters  the  lateral  wall 
of  the  cavernous  sinus  (p.  225)  and  is  conducted  to  the  orbit 
(Fig.  63). 

2.  The  Maxillary  Nerve  passes  forwards  to  the  foramen 
rotundum  and  enters  the  upper  part  of  the  pterygo-palatine 
(spheno-maxillary)  fossa.     Here  it  is  connected  to  the  spheno- 
palatine  (Meckel's)  ganglion,  which  distributes  sensory  nerves 
to  the  mucous  membrane  of  the  nose  and  palate.     It  then 
reaches  the  infra-orbital  groove,  in  the  floor  of  the  orbit,  and, 
after  supplying  the  upper  teeth,  appears  on  the  face  as  the 
infra-orbital  nerve  (p.  172). 

As  it  lies  in  the  pterygo-palatine  fossa,  the  nerve  may  be 
reached  by  a  needle  passed  medially  from  the  surface.  Advan- 
tage is  taken  of  this  fact  in  tic  douloureux  to  destroy  the  nerve 
by  injecting  absolute  alcohol  or  some  other  corrosive  fluid  into 
its  sheath.  The  needle  is  inserted  4  cm.  in  front  of  the  external 
acoustic  meatus  and  immediately  below  the  zygomatic  arch. 
As  the  coronoid  process  of  the  mandible  may  obstruct  the 
instrument  or  even  break  it,  if  the  patient  suddenly  opens  his 
mouth  during  the  operation,  it  is  better  to  keep  the  mouth  open 
by  means  of  a  gag.  The  needle  is  then  thrust  medially  through 
the  masseter,  temporal,  and  external  pterygoid  muscles  to  a 
depth  of  5  cm.  from  the  surface.  If  the  point  of  the  needle  is 
not  obstructed,  as  it  may  be  by  the  lateral  pterygoid  lamina 
(external  pterygoid  plate)  before  it  reaches  this  depth,  it  will 
have  passed  through  the  pterygo-maxillary  fissure  into  the 
pterygo-palatine  fossa.  The  contents  of  the  syringe  are  injected 
at  this  point,  and,  even  although  they  do  not  actually  pass  into 
the  nerve  sheath,  the  action  of  the  destructive  agent  is  sufficient 
to  destroy  the  nerve  and  its  branches. 


234  THE  HEAD  AND  NECK 

3.  The  Mandibular  Nerve  (p.  182)  runs  forwards  and  later- 
ally for  a  short  distance  from  the  semilunar  ganglion  and  then 
passes  downwards  through  the  foramen  ovale.  At  this  point 
it  is  joined  by  the  whole  of  the  small  (motor)  root,  which  lies 
on  the  bone  below  the  semilunar  ganglion. 

Removal  of  the  Semilunar  (Gasserian)  Ganglion.— 
The  approach  in  this  operation  and  in  ligature  of  the  main  trunk 
of  the  middle  meningeal  artery  is  similar  to  that  described  on 
p.  230,  but  a  somewhat  wider  exposure  is  necessary.  In  order 
that  this  may  be  obtained;  the  temporal  fascia  is  incised  along 
the  upper  border  of  the  zygomatic  arch  and  the  bone  is  divided 
at  each  end.  When  this  is  done  the  arch  can  be  depressed 
for  half  an  inch;  and  the  temporal  muscle  is  retracted  into  the 
interval  between  it  and  the  skull.  A  trephine  can  now  be 
applied  a  little  above  the  level  of  the  floor  of  the  middle  cranial 
fossa — which  corresponds  to  the  upper  border  of  the  undivided 
arch — and  sufficiently  far  forwards  to  avoid  the  main  trunk  of 
the  middle  meningeal  artery.  In  this  region  the  thickness  of 
the  skull  varies,  being  much  greater  below  than  above ;  and  this 
difference  must  be  borne  in  mind,  as  otherwise  the  blade  of  the 
trephine  may  tear  through  the  dura  mater  above,  before  it  has 
pierced  the  bone  below.  After  the  circular  piece  of  bone  has 
been  removed,  the  trephine  opening  is  enlarged  and  the  middle 
meningeal  artery  is  exposed  and  traced  medially  to  the  foramen 
spinosum,  where  it  is  ligated  and  divided.  Before  the  ligature 
can  be  applied,  the  dura  mater  must  be  elevated  from  the  floor 
of  the  fossa  by  blunt  dissection,  and,  after  the  artery  has  been 
dealt  with,  this  is  continued  until  the  lateral  margin  of  the 
ganglion  is  reached.  At  this  point  the  fibrous  and  serous  layers 
separate  to  enclose  the  ganglion,  and  the  elevation  of  the  fibrous 
layer  becomes  more  difficult.  The  surgeon  endeavours  to  incise 
or  break  through  the  fibrous  layer  just  beyond  the  splitting.  If 
this  is  done  successfully,  the  maxillary  nerve  is  exposed  running 
forwards  to  the  foramen  rotundum.  If,  however,  the  dura 
mater  is  incised  before  the  two  layers  separate,  the  subdural 
space  is  opened,  and  the  fluid  which  it  contains  floods  the  area 
and  greatly  increases  the  difficulty  of  the  operation.  By 
tracing  the  maxillary  nerve  backwards,  the  mandibular  nerve 
is  exposed  a  little  in  front  of  and  medial  to  the  ligated  middle 
meningeal  artery,  and  more  posteriorly  still  the  ganglion  is 
reached.  If  the  serous  layer  of  the  dura  is  elevated  in  a  medial 
direction,  the  ophthalmic  nerve  will  be  found  lying  in  the  lower 


THE  BRAIN  AND  ITS  MENINGES  235 

part  of  the  lateral  wall  of  the  cavernous  sinus  (p.  225).  The 
large  (sensory)  root  is  exposed  by  stripping  the  serous  layer  of 
the  dura  mater  backwards  off  the  ganglion,  and  it  is  then  divided. 
The  maxillary  and  mandibular  nerves  are  cut  through  as  far 
away  from  their  origin  as  possible,  and  the  ganglion  is  then  torn 
out  along  with  the  ophthalmic  nerve.  As  the  latter  lies  in 
contact  with  the  thin  endothelial  wall  of  the  cavernous  sinus 
and  is  closely  related  to  the  internal  carotid  artery  and  the 
third,  fourth,  and  sixth  cerebral  nerves  (p.  225),  few  operators 
attempt  to  divide  it  with  the  knife.  As  soon  as  the  ganglion  is 
torn  out  severe  hsemorrhage  occurs,  owing  to  the  unavoidable 
laceration  of  the  wall  of  the  cavernous  sinus,  but  it  is  readily 
controlled  by  pressure.  It  is  seldom  found  possible  to  preserve 
the  small  (motor)  root,  and,  following  the  operation,  the  muscles 
of  mastication  are  paralysed  on  that  side.  In  this  condition 
the  mandible  is  permanently  twisted  over  to  the  side  of  the  lesion 
by  the  unopposed  action  of  the  pterygoid  muscles  of  the  opposite 
side  (p.  181).  Another  common  sequela  is  thrombosis  of  the 
cavernous  sinus  with  consequent  proptosis,  chemosis,  and  retinal 
haemorrhage.  Temporary  blindness  or  permanent  impairment  of 
vision  may  result,  and  there  is  usually  some  temporary  paralysis 
of  the  ocular  muscles.  The  results  of  the  alteration  in  the 
sensibility  of  the  conjunctiva  are  described  on  p.  204. 

Contents  of  the  Posterior  Cranial  Fossa. —  The 
Medulla  Oblongata  is  the  direct  continuation  of  the  spinal 
medulla,  and  is  continuous  above  with  the  Pons.  Ventrally, 
these  two  structures  lie  on  the  basilar  portions  of  the  occipital 
and  sphenoid  bones ;  dorsally,  they  are  related  to  the  cere- 
bellum, which  also  overlaps  them  laterally.  In  the  medulla 
oblongata  and  the  pons  the  central  canal  of  the  spinal  medulla 
expands  to  form  the  fourth  ventricle,  and  the  floor  of  this  space 
contains  the  important  respiratory  and  cardiac  centres. 

On  each  side  the  transverse  fibres  of  the  pons  pass  into  the 
cerebellum  as  the  brachium  pontis  (middle  peduncle),  and  the 
region  where  the  lower  part  of  the  brachium  enters  the  cere- 
bellum is  known  as  the  cerebello-p  online  angle.  In  this  region 
the  facial  and  auditory  nerves  emerge  at  the  lower  border  of 
the  pons.  At  its  upper  extremity  the  pons  becomes  con- 
tinuous with  the  mid-brain,  which  sinks  into  the  basal  surface 
of  the  cerebral  hemispheres. 

Tumours  in  the  region  of  the  cerebello-pontine  angle  usually 
involve  the  seventh  and  eighth  cerebral  nerves.  They  may 


236  THE  HEAD  AND  NECK 

be  approached  by  the  route  described  on  p.  227  for  the 
reopening  of  the  foramen  of  Magendie.  The  operation  is 
commonly  performed  in  two  stages,  the  first  of  which  ceases 
after  the  complete  removal  of  the  lower  part  of  the  squamous 
portion  of  the  occipital  bone.  In  the  second  operation  the  occipi- 
tal sinus  is  ligatured  and  divided  along  with  the  falx  cerebelli 
(p.  225).  The  cerebellum  is  displaced  to  the  opposite  side, 
care  being  taken  not  to  press  it  against  the  floor  of  the  fourth 
ventricle,  and  access  is  thus  obtained  to  the  cerebello-pontine 
angle. 


THE  ABDOMINAL  WALLS  237 

THE   ABDOMEN   AND   PELVIS. 

THE  ABDOMINAL  WALLS. 

Surface  Landmarks.— The  Costal  Margins,  formed  by  the 
cartilages  of  the  tenth,  ninth,  eighth,  and  seventh  ribs  (the 
last  named  being  the  lowest  pair  to  reach  the  sternum),  pass 
upwards  and  medially  towards  the  sides  of  the  xiphoid  process 
and  enclose  between  them  the  Subcostal  Angle.  The  xiphoid 
process  lies  in  the  depression  at  the  apex  of  this  angle,  and  its 
pointed  lower  end  is  sometimes  bent  forwards,  being  then  easily 
palpable  beneath  the  skin. 

The  Iliac  Crest  forms  the  lower  limit  of  the  lateral  aspect  of 
the  abdominal  wall.  It  can  be  traced  forwards  to  the  Anterior 
Superior  Spine,  which  lies  on  the  same  level  as  the  second  sacral 
vertebra.  About  2  inches  behind  this  point,  a  prominent 
tubercle  can  be  felt  on  the  outer  lip  of  the  crest ;  it  is  utilised 
in  mapping  out  the  regions  of  the  abdomen. 

The  fold  of  the  groin  extends  downwards  and  medially  from 
the  anterior  superior  spine  to  the  tubercle  (spine)  of  the  pubis. 
It  overlies  the  inguinal  ligament  (of  Poupart),  which  is  slightly 
convex  downwards  owing  to  the  traction  exerted  on  it  by  the 
fascia  lata  of  the  thigh.  This  traction  is  transmitted  by  the 
ligament  to  the  lateral  abdominal  muscles,  which  are  attached 
to  it,  and  renders  them  slightly  tense  when  the  thighs  are 
extended.  In  the  examination  of  the  abdomen,  it  is  ad- 
vantageous that  the  muscles  should  be  relaxed  as  far  as 
possible,  and  to  overcome  the  traction  of  the  fascia  lata,  the 
patient's  legs  are  drawn  up,  flexing  both  the  hip  and  the  knee- 
joints.  This  is  the  posture  which  is  naturally  assumed  when 
there  is  much  distension  of  the  abdomen,  since  it  allows  the 
maximum  amount  of  relaxation  of  the  abdominal  parietes. 

The  highest  point  on  the  iliac  crest  lies  on  a  level  with  the 
lower  part  of  the  body  of  the  fourth  lumbar  vertebra.  In 
subjects  with  firm  abdominal  muscles,  the  umbilicus  also 
corresponds  to  this  level,  but  in  obese  subjects  with  lax  ab- 
dominal parietes,  it  may  sink  down  to  a  lower  plane. 

A  linear  furrow  can  be  seen,  in  muscular  subjects,  in  the 
middle  line  of  the  anterior  abdominal  wall.  It  corresponds  to 


238 


THE   ABDOMEN  AND  PELVIS 


the  Linea  Alba  (p.  247),  a  tendinous  raphe  which  separates  the 
two  recti  muscles.     It  widens  out  somewhat  above  the  umbilicus, 


FIG.  71. — Surface  Landmarks  of  the  Anterior  Abdominal  Wall,  showing 
the  lines  of  some  of  the  commoner  incisions. 


1.  Cholecystotomy  incision. 

2.  Intussusception  incision. 

3.  Pelvic  ureterotomy  incision. 


4.  Supra-pubic  cystotomy  incision. 

5.  Lumbo  -  ilio  -  inguinal     incision,     lower 

part. 


but  below  that  level  it  is  difficult  to  recognise.  In  multiparae, 
however,  and  in  children  suffering  from  rickets,  the  two  recti  are 
often  definitely  separated  below  the  umbilicus,  so  that  the 
finger  tips  may  be  introduced  between  them. 

The  lateral  margin  of  the  rectus  muscle  is  indicated  on  the 


THE  ABDOMINAL  WALLS  239 

surface  by  a  curved  furrow — the  linea  semilunaris.  It  com- 
mences below  at  the  pubic  tubercle  and  passes  midway  between 
the  umbilicus  and  the  anterior  superior  iliac  spine.  It  then 
runs  upwards  and  slightly  medially,  crossing  the  costal  margin 
near  the  tip  of  the  ninth  costal  cartilage.  Transverse  furrows 
may  sometimes  be  seen  crossing  the  upper  part  of  the  rectus. 
They  correspond  to  the  lineae  transversse  (p.  246). 

The  posterior  superior  iliac  spine  may  be  found  by  tracing 
the  iliac  crest  backwards.  Its  situation  is  marked  by  a  dimple, 
which  lies  i|  inches  from  the  middle  line.  It  is  placed  opposite 
the  middle  of  the  sacro-iliac  joint  and  on  a  level  with  the  second 
sacral  spine. 

The  spines  of  the  lumbar  vertebrae  lie  at  the  bottom  of  the 
spinal  furrow,  but  they  are  rendered  visible  when  the  trunk  is 
flexed.  On  each  side  of  the  furrow  is  the  prominence  due  to 
the  sacro-spinalis  (erector  spincz)  muscle,  the  lateral  margin  of 
which  can  be  felt,  and  sometimes  seen,  at  a  distance  of  3^  inches 
from  the  middle  line.  The  tip  of  the  twelfth  rib  can  be  recognised 
as  it  emerges  from  under  cover  of  this  border.  It  lies  about 
two  inches  above  the  midpoint  of  the  iliac  crest,  but  it  must  be 
remembered  that  the  lowest  palpable  rib  is  not  necessarily  the 
twelfth,  which  is  often  rudimentary  and  completely  hidden  by 
the  sacro-spinalis. 

The  Subcutaneous  Inguinal  Ring  (Ext.  Abdom.  Ring), 
through  which  the  spermatic  cord  leaves  the  inguinal  canal, 
lies  immediately  above  the  pubic  tubercle  (spine)  and  may 
be  examined  by  invaginating  the  skin  of  the  scrotum  from 
below.  The  anterior  surface  of  the  pubis  is  palpated,  and  the 
finger  is  carried  upwards  until  the  pubic  crest  is  reached.  It  is 
then  pressed  backwards  into  the  anterior  abdominal  wall,  and 
can  be  felt  to  pass  into  a  yielding  gap,  which  possesses  sharp 
and  definite  margins — the  subcutaneous  inguinal  ring.  If  the 
finger  is  carried  upwards,  after  reaching  the  upper  border  of 
the  pubis,  it  can  be  moved  about  quite  freely  under  the  skin 
and  fasciae  of  the  anterior  abdominal  wall. 

To  aid  topographical  description,  the  abdomen  is  subdivided  into  regions 
by  two  transverse  and  two  vertical  planes,  (a)  The  Subcostal  Plane  passes 
horizontally  through  the  body  at  the  level  of  the  most  dependent  parts  of  the 
tenth  costal  cartilages  ;  it  lies  on  a  level  with  the  upper  part  of  the  third 
lumbar  vertebra,  (ti)  The  Intertubercular  Plane  passes  horizontally  through 
the  tubercles  of  the  iliac  crests  ;  it  corresponds  in  level  with  the  upper  part  of 
the  fifth  lumbar  vertebra,  (c)  The  Right  and  (d)  the  Left  Lateral  Planes 
are  at  right  angles  to  the  transverse  planes,  and  each  bisects  the  line  joining 
the  anterior  superior  iliac  spine  to  the  symphysis  pubis. 


240  THE  ABDOMEN  AND   PELVIS 

In  this  way  nine  regions  are  mapped  out  on  the  surface.  The  three 
median  areas  are  named,  from  above  downwards,  the  epigastric,  umbilical, 
and  hypogaslric  regions  ;  the  six  lateral  areas  are,  the  right  and  left  hypo- 
chondriac, lumbar,  and  iliac  regions,  in  that  order  from  above  downwards. 

In  addition  to  the  above,,  the  Transpyloric  Plane  is 
exceedingly  useful.  It  is  a  transverse  plane,  which  passes 
horizontally  through  the  mid-point  of  the  line  joining  the 
jugular  (suprasternal)  notch  to  the  symphysis  pubis,  and  it 
crosses  the  linea  semilunaris  at  the  costal  margin  (tip  of  the 
ninth  costal  cartilage).  Posteriorly,  it  corresponds  in  level  with 
the  lower  part  of  the  body  of  the  first  lumbar  vertebra. 

The  Superficial  Fascia  in  the  upper  part  of  the  anterior 
abdominal  wall  is  directly  continuous  with  the  corresponding 
layer  of  the  thoracic  wall.  Below  it  consists  of  (i)  a  superficial 
fatty  stratum,  known  as  Camper's  fascia,  which  is  continuous 
with  the  superficial  fascia  of  the  thigh,  and  (2)  a  deeper 
membranous  layer,  which  is  in  direct  contact  with  the  aponeurosis 
of  the  external  oblique  muscle,  no  deep  fascia  intervening. 
The  latter  is  known  as  Scarpa's  fascia.  It  descends  on  each 
side  in  front  of  the  inguinal  ligament,  and  blends  with  the  fascia 
lata  of  the  thigh  immediately  below  and  nearly  parallel  to  that 
structure.  In  the  middle  line  it  is  carried  down  in  front  of  the 
pubic  bones  and  becomes  continuous  with  the  fascia  of  Colles, 
which  invests  the  penis  and  scrotum,  and  forms  the  roof  of  the 
superficial  perineal  pouch  (p.  376).  In  cases  of  extravasation 
of  urine  or  of  severe  haemorrhage  into  the  pouch  (p.  376),  the 
lines  of  attachment  of  this  fascia  are  accurately  demonstrated. 

Superficial  Nerves. — The  skin  of  the  anterior  abdominal 
wall  is  supplied  by  the  anterior  cutaneous  branches  of  the  lower 
six  thoracic  said  first  lumbar  nerves.  The  tenth  thoracic  supplies 
the  skin  in  the  neighbourhood  of  the  umbilicus.  The  ilio- 
hypogastric  and  ilio-inguinal  nerves  are  both  derived  from  L.  i  ; 
the  latter  reaches  the  surface  at  a  lower  level  than  the  f ormej,  and 
supplies  the  skin  over  the  tubercle  (spine)  of  the  pubis,  the  upper 
part  of  the  scrotum,  and  the  proximo-medial  part  of  the  thigh. 

On  the  lateral  aspect  of  the  abdominal  wall  the  skin  is  supplied 
by  the  lateral  cutaneous  branches  of  the  seventh-eleventh 
thoracic  nerves.  Corresponding  branches  from  the  twelfth 
thoracic  and  ilio-hypogastric  descend  over  the  iliac  crest  to 
supply  the  skin  of  the  gluteal  region. 

The  anterior  rami  (ant.  prim,  divisions),  which  give  off 
these  various  branches,  descend  obliquely  as  they  pass  round 


FIG.  72.  — The  Nerve-Supply  of  the  Skin  on  the  Ventral  Aspect  of  the  Trunk. 
The  whole  of  the  area  shown  in  the  diagram  is  supplied  by  branches 
from  the  anterior  rami  (primary  division)  of  the  spinal  nerves. 

G.A,  Great  auricular  nerve;  S.C,  N.  cutaneus  colli ;  S.Ci.,  Supra-clavicular  nerves; 
ACR,  Posterior;  ST,  Middle;  CL,  anterior;  T.2-I2,  Lateral  and  anterior  branches 
of  thoracic  nerves;  I.H,  Ilio-hypogastric  nerve;  I.I,  Ilio-inguinal  nerve;  CIRC, 
Cutaneous  branch  of  axillary  nerve  ;  L.  I.C,  Medial  cutaneous  nerve  of  the  arm  (O.T. 
lesser  internal  cutaneous  nerve);  I.H,  Intercosto-brachial ;  I.C,  Medial  cutaneous 
nerve  of  the  forearm  (O.T.  internal  cutaneous);  M.S,  Cutaneous  branch  of  radial 
nerve  ;  E.C,  Lateral  cutaneous  nerves;  G.C,  Lumbo-inguinal  nerve;  M.C1  2,  Inter- 
mediate cutaneous  nerves  ;  I.C1,  Branch  of  medial  cutaneous  nerve  ;  P,  Branches  of 
pudendal  nerve  ;  S.Sc,  Branches  of  posterior  cutaneous  nerve  of  the  thigh. 

On  the  other  side  a  schematic  representation  is  given  of  the  areas  supplied  by  the  above 
nerves,  the  numerals  indicating  the  spinal  origin  of  the  branches  of  distribution  to 
each  area. 


241 


16 


242  THE  ABDOMEN  AND  PELVIS 

the  abdominal  wall.  Their  obliquity  can  be  appreciated  if  the 
course  of  the  eighth  intercostal  nerve  is  examined.  Posteriorly, 
it  is  placed  at  the  level  of  the  inferior  angle  of  the  scapula,  but 
anteriorly  it  ends  midway  between  the  xiphoid  process  and  the 
umbilicus.  The  lateral  cutaneous  branches  descend  under  cover 
of  the  fascia  before  they  come  to  the  surface,  and  so,  despite  the 
oblique  course  of  the  main  trunks,  the  terminal  branches  supply 
areas  of  skin,  which  are  almost  horizontal  (Fig.  72). 

The  skin  of  the  posterior  abdominal  wall  is  supplied  by  the 
posterior  rami  (primary  divisions)  of  the  lower  thoracic  and  upper 
lumbar  nerves  (L.  i,  2,  and  3).  (Fig.  3). 

These  incline  downwards  in  the  fascia,  and  become  cutaneous 
on  the  same  horizontal  plane  as  the  lateral  and  anterior  branches. 

In  Herpes  Zoster  the  affected  areas  do  not  map  out  the 
course  of  a  thoracic  nerve,  but  the  terminations  of  its  cutaneous 
branches.  They  therefore  form  horizontal  strips  round  the 
body,  and  they  correspond  exactly  to  the  areas  in  which  the 
"  girdle  pains  "  are  experienced  in  locomotor  ataxia. 

Referred  Pain. — The  anterior  rami  (ant.  prim,  divisions) 
of  the  thoracic  and  of  the  first  (and  sometimes  second) 
lumbar  nerves  are  connected  to  the  corresponding  ganglia  of 
the  sympathetic  by  both  white  and  grey  rami  communicantes 
(p.  125).  The  nerve-supply  to  the  abdominal  viscera  is  derived 
from  the  lower  eight  thoracic  and  the  first  lumbar  segments 
and,  consequently,  afferent  impulses  from  the  viscera  reach 
the  same  segments  in  the  spinal  medulla  (cord)  as  do  the  afferent 
impulses  from  the  skin  of  the  abdominal  wall.  In  pathological 
conditions  the  afferent  impulses  from  the  viscera  may  become 
so  altered,  either  in  strength  or  character,  as  to  overflow  those 
cells  for  which  they  were  originally  intended,  and  stimulate 
those  neighbouring  cells  which  are  accustomed  to  receive 
impulses  from  the  skin  of  the  abdominal  wall  (Fig.  73).  When 
the  stimuli  from  these  latter  cells  reach  the  brain,  they  are 
interpreted  as  painful  sensations  affecting  the  skin  area  supplied 
by  the  segment  of  the  spinal  medulla  which  is  involved.  Pain 
of  this  variety,  which  may  be  felt  in  a  different  region  from  the 
viscus  at  fault,  is  spoken  of  as  referred  pain,  and  the  whole  reflex 
is  called  the  "  viscero- sensory  reflex"  (Mackenzie).  The  areas 
in  which  referred  pain  may  be  felt  in  pathological  conditions  of 
the  various  viscera  are  dealt  with  under  each  individual  organ 
(pp.  298,  312,  etc.). 

The  Superficial  Veins  of  the  abdominal  wall  may  be  divided 


THE  ABDOMINAL  WALLS 


243 


into  an  upper  and  a  lower  group.  The  upper  veins  join  the 
internal  mammary,  intercostal,  and  lateral  (long)  thoracic  veins, 
and  so  return  their  blood  to  the  heart  via  the  vena  cava  superior. 
The  lower  veins  join  the  femoral,  and  consequently  drain  into 
the  vena  cava  inferior.  These  two  groups  communicate  freely 
with  one  another  through  the  thoraco-epigastric  vein,  which 
ascends  from  the  groin  to  the  region  of  the  axilla.  Owing  to 
their  position  these  veins  are  capable  of  considerable  increase 
in  size.  In  obstruction  of  the  vena  cava  inferior  this  anastomosis 

Cerebral  cortex  in 
connection  with  skin 


Cerebral  cortex 
in  connection 
with  viscus 


Cells  in  anterior  column  of 
spinal  medulla 

FIG.  73. — Diagram  to  illustrate  the  Viscero  -  Sensory  and  Viscero-Motor 
Reflexes.  The  arrows  indicate  the  passage  of  the  afferent  impulses  from 
the  viscus  to  the  cortex,  and  show  how  they  may  overflow  so  as  to 
stimulate  the  neighbouring  cells  in  the  spinal  medulla. 

provides  a  new  channel  for  the  return  of  blood  from  the  lower 
limbs,  and  the  thoraco-epigastric  vein  becomes  specially  enlarged. 
Further,  the  para-umbilical  vein  (of  Sappey)  passes  from  the  left 
branch  of  the  portal  vein  along  the  ligamentum  teres  to  the 
umbilicus,  where  it  communicates  with  both  groups.  Varicosity 
of  the  superficial  abdominal  veins  may  therefore  occur  in 
portal  obstruction,  but  in  this  case  the  blood -flow  in  the 
distended  veins  is  from  the  umbilicus  both  upwards  and  down- 
wards, whereas  in  obstruction  of  the  vena  cava  inferior  the 
blood-flow  is  in  an  upward  direction  only. 

The  Lymph  Vessels  of  the  whole  abdominal  wall,  below 
the  level  of  the  umbilicus,  join  the  superficial  sub-inguinal  lymph 


244  THE  ABDOMEN  AND  PELVIS 

glands  (p.  400).  Above  the  umbilicus,  those  from  the  anterior  ab- 
dominal wall  join  the  pectoral  glands,,  while  those  from  the  pos- 
terior abdominal  wall  terminate  in  the  subscapular  group  (p.  35). 

Lymph  vessels  from  the  liver  descend  along  the  ligamentum 
teres  to  the  umbilicus,  where  they  establish  communications 
with  the  lymphatics  of  the  anterior  abdominal  wall.  Cancer  of 
the  umbilicus  may  occur  secondarily  to  cancer  of  the  liver,  and 
the  infection  may  spread  to  the  lymph-glands  in  the  groin. 

Lateral  and  Anterior  Muscles  of  the  Abdominal 
Wall. — The  external  oblique  muscle  arises  from  the  lower 
eight  ribs,  and  its  fibres  are  mainly  directed  downwards,  forwards, 
and  medially.  Above,  it  interdigitates  with  the  serratus  anterior 
(serr.  magnus),  and  the  deep  fascia  which  covers  both  muscles 
forms  a  continuous  sheet  (p.  31).  The  lowermost  (or  posterior) 
fibres  run  vertically  downwards,  and  are  inserted  into  the 
anterior  half  of  the  iliac  crest,  so  that  between  the  last  rib  and 
the  crest  the  external  oblique  has  a  free  posterior  border,  which 
forms  the  lateral  boundary  of  the  lumbar  triangle  (of  Petit). 
The  remaining  fibres  become  aponeurotic  near  the  linea  semi- 
lunaris,  and  pass  in  front  of  the  rectus  abdominis  to  reach 
the  xiphoid  process,  linea  alba,  pubic  symphysis,  and  crest. 
No  muscular  fibres  are  found  below  a  line  joining  the  anterior 
superior  spine  of  the  ilium  to  the  umbilicus. 

The  lower  border  of  the  aponeurosis  of  the  external  oblique 
forms  the  inguinal  ligament  (of  Poupart),  which  extends  from 
the  anterior  superior  spine  to  the  pubic  tubercle  (spine).  It  is 
bent  upwards  and  backwards  on  itself  so  that  the  upper  surface 
of  the  ligament  is  grooved.  The  lacunar  ligament  (of  Gimbernat) 
is  the  medial  part  of  the  folded-back  margin  of  the  inguinal 
ligament.  It  is  attached  to  the  pecten  pubis  (ilio-pectineal  line) 
and  possesses  a  free,  crescentic,  lateral  margin,  which  is  intimately 
related  to  the  femoral  (crural)  ring  (p.  403). 

Just  above  the  medial  end  of  the  inguinal  ligament  the 
spermatic  cord  pierces  the  aponeurosis  of  the  external  oblique, 
and  the  opening  through  which  it  passes  is  known  as  the 
subcutaneous  inguinal  (ext.  abdom.)  ring  (pp.  239  and  254). 

The  Internal  Oblique  lies  under  cover  of  the  preceding 
muscle.  It  arises  from  the  lumbo- dorsal  fascia  (p.  269), 
through  which  it  gains  attachment  to  the  lumbar  spines,  so  that 
it  possesses  no  free  posterior  border — the  iliac  crest,  and  the 
lateral  two -thirds  of  the  inguinal  ligament.  The  general 
direction  of  the  fibres  is  upwards,  forwards,  and  medially. 


THE  ABDOMINAL  WALLS 


245 


The  uppermost  fibres  are  inserted  into  the  lower  ribs  and  their 
cartilages  ;  the  intermediate  fibres  form  an  aponeurosis,  which  is 
inserted  into  the  linea  alba ;  the  lowest  fibres  arch  over  the 
spermatic  cord  and  are  inserted  behind  it  as  it  leaves  the  inguinal 


Greater  occipital  nerve 

Third  occipital  nerve 

Sterno-mastoid 

Lesser  occipital  nerve 

Trapezius 


Deltoid 


Semispinalis  capitis  (O.T.  complexus) 

Splenius  capitis 
Cervical  nerves  to  trapezius 
Accessory  nerve 

Ascending  br.  of  transverse  cervic 
Levator  scapulae 

Descending  br.  of  t 
cervical  artery  and 
scapulas  nerve 

Rhomboideus  rr 


_  Trapezius 
(reflected) 

Rhomboideus 
major 

Teres  major 


Serratus  ante 


Serratus  posterior  inferior 
Latissimus  dorsi 
External  oblique  muscle 
Trigonum  lumbale  (Petiti) 

Glutseus  medius 
Glutseus  maximus 


FIG.  74.  — The  Muscles  on  the  Dorsal  Aspect  of  the  Trunk. 

canal.    The  latter  blend  with  fibres  of  the  transversus  to  form 
the  Falx  Inguinalis  Aponeurotica  (Conjoined  Tendon). 

The  Transversus  Abdominis  is  the  deepest  muscular  layer 
of  the  lateral  abdominal  wall.  It  arises  (i)  from  the  internal 
surfaces  of  the  lower  six  costal  cartilages,  interdigitating  with 
the  diaphragm,  so  that  the  fascia  on  its  deep  surface 

16  a 


External  divisions  of 
posterior  rami  of  — 
lumbar  nerves 


246  THE  ABDOMEN  AND  PELVIS 

(f.  transversalis)  is  continuous  with  the  layer  on  the  under 
surface  of  the  diaphragm ;  (2)  from  the  lumbo-dorsal  fascia ; 
and  (3)  from  the  iliac  crest  and  the  lateral  third  of  the  inguinal 
ligament.  The  general  direction  of  the  fibres  is  horizontal,  but 
the  lowest  fibres  turn  downwards  to  be  inserted  into  the  pecten 
pubis  (ilio-pectineal  line)  where  they  take  part  in  the  formation 
of  the  falx  inguinalis  (conjoined  tendon).  The  rest  of  the  muscle 
forms  an  aponeurosis  which  gains  attachment  to  the  linea  alba. 
This  aponeurosis  is  extremely  narrow  above,  but  it  gradually 
widens  below. 

The  Eectus  Abdominis  muscle  arises  from  the  pubis  and 
extends  upwards  in  the  interval  between  the  linea  alba  and  the 
linea  semilunaris  (p.  239).  It  is  inserted  into  the  anterior 
aspects  of  the  fifth,  sixth,  and  seventh  costal  cartilages.  Irregular 
tendinous  intersections  cross  the  muscle,  one  at  the  umbilicus, 
a  second  at  the  xiphoid  process,  and  a  third  midway  between 
the  other  two.  They  are  known  as  the  Linece  Transverse? ,  and 
are  strongly  adherent  to  the  anterior  wall  of  the  rectus  sheath. 

The  sheath  of  the  rectus  abdominis  is  a  strong  but  incomplete 
aponeurotic  envelope,  which  is  formed  by  the  aponeuroses  of  the 
three  lateral  abdominal  muscles.  It  is  differently  constituted 
in  its  upper  and  lower  parts. 

(a)  Above  the  level  of  the  midpoint  between  the  umbilicus  and 
the  symphysis  pubis. — The  aponeurosis  of  the  internal  oblique 
splits  into  an  anterior  and  a  posterior  lamella  at  the  lateral 
margin  of  the  rectus.    The  anterior  layer  blends  with  the 
aponeurosis  of  the  external  oblique,  and  forms  the  anterior  wall 
of  the  sheath,  while  the  posterior  layer  blends  with  the  aponeurosis 
of  the  transversus  to  form  the  posterior  wall.    Where  the 
muscle  rests  on  the  costal  cartilages  near  its  insertion,  the 
posterior  wall  of  its  sheath  is  deficient,  as  the  internal  oblique 
and  transversus  abdominis  do  not  pass  upwards  beyond  the 
seventh  costal  cartilage.     In  its  upper  part  the  posterior  wall 
is  not  entirely  aponeurotic,  as,  owing  to  the  narrowness  of  its 
aponeurosis,  the  upper  fleshy  fibres  of  the  transversus  lie  behind 
the  rectus  abdominis  and  almost  reach  the  linea  alba. 

(b)  Below  the  level  of  the  midpoint  between  the  umbilicus  and 
symphysis  pubis. — In  this  region  the  sheath  of  the  rectus  is 
formed  anteriorly  by  the  blended  aponeuroses  of  the  external 
oblique,  internal  oblique,  and  transversus.    The  posterior  wall 
terminates  in  a  free  crescentic  lower  margin — the  linea  semi- 
circularis  (semilunar  fold  of  Douglas) — at  the  level  indicated 


THE  ABDOMINAL  WALLS 


247 


above.  This  margin  is  usually  fused  with  the  underlying  trans- 
versalis  fascia,  which  is  in  direct  contact  with  the  rectus  ab- 
dominis  in  the  lower  part  of  the  abdominal  wall. 

Little  difficulty  is  experienced  in  freeing  the  rectus  abdominis 
from  the  posterior  wall  of  the  sheath,  but  the  muscle  is  much 
more  firmly  adherent  to  the  anterior  wall,  especially  opposite 
the  lineae  transversse. 


FIG.  75. — Diagram  of  Transverse  Sections  through  the  Rectus  Abdominis 
Muscles,  to  illustrate  the  method  of  closing  wounds  in  the  infra-umbilical 
part  of  the  linea  alba. 

I.  The  dotted  line  indicates  the  incision  in  the  linea  alba. 

II.  Prior  to  closure  of  the  median  wound,  an  incision  has  been  made  on  each  side 
into  the  anterior  wall  of  the  sheath. 

III.  Closure  of  the  median  wound.  The  deepest  suture  includes  the  cut  edges  of  the 
parietal  peritoneum  as  well  as  the  sheath.  The  two  recti  and  the  anterior  walls  of  their 
sheaths  may  be  united  by  one  continuous  suture  and  not  by  two  layers  of  sutures  as 
shown  in  the  figure. 

Incisions  in  the  Abdominal  Wall.— Vertical  Incisions 
through  the  linea  alba  have  several  advantages,  (i)  They 
are  almost  bloodless.  (2)  No  muscle  fibres  are  cut  across.  (3) 
No  nerves  are  injured.  (4)  They  give  access  to  both  sides  of 
the  abdomen. 

When  the  linea  alba  and  the  subjacent  fascia  transversalis 
have  been  incised,  the  extra-peritoneal  fat  is  exposed.  This  is 
a  thin  layer  inferiorly,  but  it  is  much  thicker  above  the  umbilicus. 

Owing  to  the  close  approximation  of  the  recti  below  the 
umbilicus  there  is  very  little  tendency  for  ventral  hernia  to  occur 
after  incisions  through  the  lower  part  of  the  linea  alba,  but 
vertical  incisions  through  the  supra-umbilical  part  of  this  line 


248  THE  ABDOMEN  AND  PELVIS 

tend  to  leave  a  weakness  in  the  anterior  abdominal  wall  when 
they  heal.  This  is  due  to  the  normally  existing  interval  between 
the  upper  portions  of  the  two  recti  muscles,  and  maybe  prevented 
in  the  following  way.  A  vertical  incision,  the  length  of  the 
original  wound,  is  made  through  the  anterior  wall  of  each  rectus 
sheath  along  its  medial  border,  and  the  medial  edges  of  these 
cuts  are  stitched  together  (Fig.  75)  by  sutures  which  also  pass 
through  the  peritoneum.  In  this  way  the  gap  is  bridged  by 
strong  tissue  which  is  not  too  tightly  stretched.  The  medial 
edges  of  the  recti  and  the  anterior  layers  of  their  sheaths  are 
stitched  together  over  the  newly-formed  deep  layer  of  the 
abdominal  wall  (Stiles). 

The  same  method  may  be  adopted  in  the  radical  cure  of  a 
ventral  hernia  in  this  region. 

The  "Gridiron  Incision"  is  planned  so  as  to  minimise, 
as  far  as  possible,  the  subsequent  weakness  in  the  abdominal 
wall.  The  fibres  of  the  various  muscles  are  not  cut  across  but 
are  separated  in  the  direction  in  which  they  run.  It  is  most 
frequently  employed  in  inguinal  colotomy  and  in  the  oblique  ap- 
proach to  the  vermiform  process  (appendix)  over  M'Burney's  point 
(which  lies  at  the  junction  of  the  middle  and  lower  thirds  of  the 
line  joining  the  umbilicus  to  the  anterior  superior  iliac  spine). 

The  skin  and  fascia  are  divided  downwards  and  medially, 
exposing  the  glistening  aponeurosis  of  the  external  oblique, 
and  in  the  upper  part  of  the  wound  some  of  its  muscular  fibres. 
The  aponeurosis  is  split  in  the  line  of  the  incision,  i.e.  parallel 
to  the  direction  of  the  muscular  fibres,  and  the  split  is  continued 
upwards  into  the  fleshy  part  of  the  muscle.  When  the  cut 
edges  are  retracted,  the  lower  part  of  the  internal  oblique  is 
exposed.  In  this  region  the  fibres  of  both  the  internal  oblique 
and  the  transversus  abdominis  (transversalis)  are  practically 
horizontal,  but  in  the  lower  part  of  the  wound  they  turn 
downwards  to  form  the  falx  inguinalis  (conjoined  tendon).  These 
two  parts  of  both  muscles  are  separated  from  one  another  along 
a  horizontal  line  at  the  level  of  the  anterior  superior  spine.  The 
fascia  transversalis,  which  is  now  exposed,  and  the  underlying 
peritoneum  are  opened  at  the  same  time,  but  great  care  must 
be  exercised,  as  the  bowel  may  be  adherent  to  the  latter. 

If  the  muscular  interval,  obtained  in  this  way,  does  not  give 
sufficient  access,  the  split  may  be  extended  both  laterally  and 
medially.  In  the  former  direction  it  may  be  carried  to  the 
anterior  superior  spine,  exposing  the  ascending  branch  of  the 


THE  ABDOMINAL  WALLS 


249 


circumflex  iliac  artery  (p.  253) ;  in  the  latter,  it  is  continued 
along  the  same  horizontal  line  through  the  anterior  wall  of 


Transpyloric 
plane 


Right  later 
plar 


Xiphoid  process 


FIG.  76. — Surface  Landmarks  of  the  Anterior  Abdominal  Wall,  showing 
the  lines  of  some  of  the  commoner  incisions. 

5.  Infra-umbilical  median  incision. 


1.  Exposure  of  gall-bladder. 

2.  Supra-umbilical  median  incision 

3.  Gastrostomy  incision. 

4.  Gridiron  incision. 


6.  Colostomy  incision  (through  rectus). 

7.  Colostomy  incision. 

8.  Exposure  of  spleen  and  left  colic  flexure. 


the  rectus  sheath.  The  muscle  is  retracted  medially,  and  the 
posterior  wall  of  the  sheath  is  similarly  divided,  care  being  taken 
to  avoid  or  to  ligate  the  inferior  (deep)  epigastric  artery  (p.  253). 
The  abdomen  may  also  be  opened  through  the  rectus 
sheath.  In  the  upper  third,  this  route  gives  access  to  the 


250  THE  ABDOMEN  AND  PELVIS 

gall-bladder  through  the  right  rectus,  and  to  the  stomach 
through  the  left  rectus.  The  direction  of  the  incision  may 
vary  as  it  passes  through  the  skin  and  fascia,  but  the  anterior 
layer  of  the  sheath  and  the  muscle  are  split  vertically,  i.e. 
parallel  to  the  muscular  fibres,  or  the  rectus  may  be  freed  and 
retracted.  Finally,  the  posterior  layer  of  the  sheath  and  the 
muscular  fibres  of  the  trans  versus  (p.  246)  are  divided,  together 
with  the  subjacent  and  partially  adherent  fascia  trans versalis. 
This  exposes  the  extra-peritoneal  fat,  which  forms  a  layer  of 
considerable  thickness  in  this  region.  After  it  has  been  cut 
through,  the  parietal  peritoneum  becomes  visible. 

In  the  lower  third,  this  route  may  be  employed  for 
appendicectomy.  As  soon  as  the  rectus  is  split  or  retracted, 
the  fascia  transversalis  is  exposed,  as  the  posterior  wall  of  the 
sheath  is  deficient  in  this  region  (p.  246).  The  inferior  (deep) 
epigastric  artery,  which  lies  on  the  fascia  transversalis  (p.  253), 
is  also  exposed,  and  it  may  either  be  retracted  or  ligated.  The 
extra-peritoneal  fat  is  very  scanty,  and  may  only  be  represented 
by  a  little  areolar  tissue. 

Occasionally,  e.g.  for  the  removal  of  large  tumours  of  the 
kidney  or  malignant  growths  of  the  colon,  it  may  be  necessary 
to  cut  through  the  lateral  abdominal  muscles  in  a  vertical 
direction ;  i.e.  across  the  muscular  fibres.  The  incision  com- 
mences above  at  the  lower  border  of  the  tenth  costal  cartilage, 
and  descends  towards  the  anterior  superior  iliac  spine.  Below, 
it  passes  medially,  above  the  inguinal  ligament.  It  penetrates 
all  the  muscles  of  the  abdominal  wall  along  the  same  line  and 
is  limited,  medially,  by  the  inferior  (deep)  epigastric  artery  and 
the  abdominal  inguinal  (int.  abd.)  ring. 

The  Nerves  of  the  Abdominal  Wall  run  in  the  interval 
between  the  internal  oblique  and  the  transversus  abdominis — 
the  upper,  horizontally ;  the  lower,  downwards  and  medially. 
After  they  leave  the  costal  margin,  the  seventh  and  eighth 
intercostal  nerves  run  upwards  and  medially  behind  the  rectus, 
while  the  ninth  and  tenth  run  transversely.  The  nerves  of  the 
abdominal  wall  include  the  lower  seven  thoracic  nerves  and  the 
first  lumbar  nerve,  which  is  represented  by  two  branches,  the 
ilio-hypogastric  and  the  ilio-inguinal.  As  they  pass  forwards 
they  supply  the  lateral  muscles  of  the  abdominal  wall,  and  at 
the  linea  semilunaris  all,  save  the  ilio-hypogastric  and  ilio- 
inguinal,  enter  the  rectus  sheath.  Finally  they  supply  the 
rectus  muscle,  and  pierce  it  to  become  cutaneous  (p.  240). 


THE  ABDOMINAL  WALLS  251 

Their  nerve  -  supply  indicates  that  the  muscles  of  the 
abdominal  wall  have  arisen  from  the  fusion  of  the  muscles  of 
six  or  seven  adjoining  segments,  which  were  originally  quite 
independent.  In  consequence  of  its  segmental  character  the 
rectus  abdominis  may  be  cut  across  in  operations  and  reunited 
with  much  less  functional  loss  than  results  from  section  of 
muscles  which  have  not  arisen  in  this  way  (e.g.  biceps  brachii). 
In  addition,  one  or  more  adjoining  segments  may  become 
contracted,  while  the  rest  of  the  muscle  is  relaxed.  Such 
localised  areas  of  contraction  may  be  due  to  cramp,  but  they 
are  frequently  found  in  connection  with  pathological  conditions 
of  the  abdominal  (p.  354)  or  even  thoracic  viscera.  These 
cases  are  examples  of  the  "  viscero-motor  reflex  "  (Mackenzie). 
The  afferent  impulses  from  the  viscus  at  fault  to  the  central 
nervous  system  not  only  set  up  the  viscero-sensory  reflex 
(p.  242)  but  they  may  also  "  overflow  "  into  the  motor  cells  of 
the  anterior  column  (horn)  of  the  grey  matter.  The  efferent 
fibres  of  these  cells  supply  the  corresponding  muscle  segment, 
and  in  this  way  the  localised  contracted  areas  may  be  explained 

(Kg.  73). 

In  making  incisions  through  the  abdominal  wall  it  is 
important  that  the  position  and  course  of  the  nerves  should 
be  borne  in  mind,  for  although  one  may  be  injured  without  any 
undesirable  after-effects,  the  abdominal  wall  never  completely 
recovers  its  muscular  tone  after  section  of  the  motor  nerves. 
For  this  reason,  when  possible,  the  incisions  are  planned  so  as 
to  avoid  injuring  the  nerves,  e.g.  the  median  and  gridiron 
incisions.  In  opening  the  abdomen  through  the  rectus  abdominis 
the  muscle  should,  when  possible,  be  retracted  to  the  lateral 
side  for  the  same  reason. 

A  large  rectangular  incision  is  employed  by  Perthes  in 
order  to  expose  the  region  of  the  gall-bladder  and  the  bile-duct. 
The  vertical  limb  begins  a  little  below  the  xiphoid  process,  and 
descends  one  finger's  breadth  to  the  right  of  the  median  plane, 
almost  to  the  umbilicus.  The  horizontal  limb  passes  to  the 
right  from  the  lower  end  of  the  vertical  limb.  The  anterior  wall 
of  the  rectus  sheath  is  divided  in  the  line  of  the  vertical  part  of 
the  incision,  and  the  medial  border  of  the  muscle  is  defined. 
The  finger  can  then  be  inserted  behind  the  rectus  so  as  to 
separate  it  from  the  posterior  wall  of  its  sheath. 

Two  transverse  rows  of  sutures  are  passed  through  the 
anterior  wall  of  the  sheath  and  through  the  muscle,  in  the  line 


252  THE  ABDOMEN  AND  PELVIS 

of  the  horizontal  part  of  the  incision.  When  this  has  been  done, 
the  anterior  wall  of  the  sheath  and  the  rectus  may  be  cut  across 
between  the  two  rows  of  sutures,  which  serve  to  prevent 
retraction  of  the  cut  ends  of  the  muscle  A  large  triangular 
musculo-cutaneous  flap  can  then  be  turned  upwards  and  to 
the  right,  until  the  terminal  parts  of  the  intercostal  nerves  are 
exposed  as  they  pass  forwards  into  the  rectus.  The  posterior 
wall  of  the  sheath,  together  with  the  underlying  transversalis 
fascia  and  parietal  peritoneum,  is  divided  by  an  oblique  incision, 
which  is  placed  medial  to  the  nerves  and  nearly  parallel  to  the 
costal  margin. 

This  method  of  approach,  while  providing  good  access  to 
the  region  of  the  gall-bladder,  produces  little  weakening  of  the 
abdominal  wall,  since  none  of  the  motor  nerves  are  injured.  In 
addition  there  is  little  danger  of  the  occurrence  of  a  post-operative 
hernia,  as  the  anterior  and  posterior  walls  of  the  rectus  sheath  are 
not  divided  in  the  same  line. 

An  incision,  of  varying  length,  two  inches  below  and 
parallel  to  the  right  costal  margin,  gives  good  access  to  the 
gall-bladder.  In  obese  subjects  it  may  be  necessary  to  prolong 
the  lateral  part  of  the  incision  in  a  downward  direction.  If, 
during  this  operation,  the  lower  part  of  the  patient's  back  is 
supported  by  a  sand-bag,  pillow,  etc.,  the  forward  convexity  of 
the  lumbar  region  is  increased,  the  viscera  are  pressed  forwards, 
and  the  wound  gapes  so  as  to  afford  excellent  access.  Incisions 
planned  to  preserve  the  nerves,  i.e.  made  at  right  angles  to  the 
costal  margin,  cannot  be  made  to  gape  in  the  same  way. 

In  all  cases  where  the  abdominal  muscles  are  cut  across  the 
direction  of  their  fibres,  the  wall  must  be  sewn  up  in  layers  to 
diminish  the  subsequent  weakness  as  far  as  possible. 

The  Transversalis  Fascia  covers  the  deep  surface  of  the 
transversus  muscle,  and,  inferiorly,  it  extends  beyond  the  lower 
border  of  the  muscle  to  reach  the  inguinal  ligament.  It  extends 
medially  behind  the  posterior  wall  of  the  rectus  sheath,  with 
which  it  partially  blends.  In  the  lower  part  of  the  anterior 
abdominal  wall,  where  the  rectus  sheath  is  deficient  posteriorly, 
the  transversalis  fascia  lies  in  direct  contact  with  the  rectus 
abdominis.  Above,  it  is  continuous  with  the  fascia  on  the  under 
surface  of  the  diaphragm,  and  below  with  the  pelvic  fascia. 
The  connections  of  the  transversalis  fascia  on  the  posterior 
abdominal  wall  are  described  on  p.  271. 

Arteries    of    the    Anterior    Abdominal    Wall. — 


THE   ABDOMINAL  WALLS  253 

(a)  SUPERFICIAL.  —  The  arteries  which  supply  the  lower 
part  of  the  wall  are  all  derived  from  the  femoral,  and  ascend 
from  the  thigh,  (i)  The  Superficial  Epigastric  crosses  the 
middle  of  the  inguinal  ligament.  (2)  The  Superficial  External 
Pudendal  runs  medially  across  the  spermatic  cord.  Both  of 
these  vessels  are  usually  divided  in  the  incisions  for  inguinal 
hernia.  (3)  The  Superficial  Circumflex  Iliac  supplies  the 
skin  in  the  neighbourhood  of  the  anterior  superior  iliac  spine. 

(b)  DEEP.— i.  The  Inferior  (Deep)  Epigastric  artery  arises 
from  the  external  iliac,  just  above  the  inguinal  ligament,  and 
ascends  in  the  direction  of  the  umbilicus.  At  first  it  lies  in  the 
extra-peritoneal  fat,  but  it  soon  pierces  the  fascia  transversalis, 
and  enters  the  rectus  sheath  by  passing  in  front  of  the  linea 
semicircularis  (semilunar  fold  of  Douglas).  It  then  runs 
upwards  on  the  deep  surface  of  the  rectus  and  anastomoses 
with  the  superior  epigastric,  which  is  descending  from  the 
internal  mammary. 

The  inferior  epigastric  artery  may  be  injured  if  the  oblique 
appendicular  wound  (p.  248)  is  increased  downwards  and 
medially,  or  when  the  rectus  is  split  longitudinally. 

The  origin  of  the  inferior  epigastric  lies  half  an  inch  above 
the  inguinal  ligament,  and  midway  between  the  anterior  superior 
iliac  spine  and  the  symphysis  pubis.  Its  course  may  be  indicated 
by  a  line  drawn  from  its  point  of  origin  towards  the  umbilicus. 

The  important  relations  of  this  vessel  to  the  inguinal  canal 
and  to  the  varieties  of  inguinal  hernia  are  described  on  pp.  255 
and  263. 

2.  The  Deep  Circumflex  Iliac  artery  also  arises  from  the 
external  iliac,  just  above  the  inguinal  ligament.  It  passes 
upwards  and  laterally  along  the  inguinal  ligament  and  the 
iliac  crest.  Just  behind  the  anterior  superior  spine  it  gives  off 
a  moderately  large  branch,  which  ascends  between  the  internal 
oblique  and  transversus,  and  may  be  injured  when  the  gridiron 
appendicular  incision  is  prolonged  laterally. 

The  Inguinal  Region. — The  Inguinal  Canal  is  an  oblique 
cleft  in  the  anterior  abdominal  wall  above  the  medial  half  of 
the  inguinal  ligament.  In  the  male  it  contains  the  spermatic 
cord,  and  this  structure  enters  the  canal  at  its  upper  end  through 
the  Abdominal  Inguinal  (Int.  Abd.)  Ring,  which  is  situated  in 
the  fascia  transversalis  about  half  an  inch  above  the  inguinal 
ligament,  midway  between  the  anterior  superior  iliac  spine  and 
the  pubic  symphysis.  The  canal  is  about  one  and  a  half  inches 


254  THE  ABDOMEN  AND  PELVIS 

long,  and  extends  downwards,,  forwards,  and  medially  to  the 
Subcutaneous  Inguinal  (Ext.  Abd.)  Ring,  where  the  spermatic 
cord  emerges  from  the  abdominal  wall.  The  subcutaneous 
inguinal  ring  is  a  triangular  opening  situated  in  the  external 
oblique  aponeurosis.  Its  base  is  formed  by  the  lateral  part 
of  the  pubic  crest,  and  its  apex  is  directed  upwards  and  laterally. 
The  upper  (or  medial)  and  lower  (or  lateral)  margins  of  the 
opening,  known  as  the  Crura  or  Pillars.,  are  formed  by  the 
external  oblique  aponeurosis. 

The  upper  or  deep  end  of  the  canal  is  therefore  placed 
lateral  to  the  lower  or  superficial  end.  This  arrangement 
greatly  diminishes  the  weakness  produced  in  the  anterior 
abdominal  wall  by  the  passage  through  it  of  the  spermatic  cord, 
for  when  the  viscera  are  pressed  against  the  abdominal  inguinal 
(int.  abd.)  ring,  e.g.  in  coughing,  they  are  at  the  same  time 
pressed  against  the  posterior  wall  of  the  canal,  which  they  force 
into  apposition  with  its  anterior  wall.  In  this  way  the  canal  is 
practically  closed. 

The  Anterior  Wall  of  the  inguinal  canal  is  formed  by  the 
aponeurosis  of  the  external  oblique  ;  in  addition,  those  fibres  of 
the  internal  oblique  which  arise  from  the  middle  of  the  inguinal 
ligament  assist  in  its  formation  in  the  lateral  third  of  the  canal. 

In  order  to  expose  the  spermatic  cord  as  it  lies  in  the  inguinal 
canal,  it  is  necessary  to  cut  through  the  external  oblique 
aponeurosis  from  the  lower  crus  (pillar)  of  the  subcutaneous 
inguinal  ring  for  ij  inches,  parallel  to  the  inguinal  ligament. 
Medially,  this  incision  exposes  the  cord,  but  laterally  the  cord 
is  still  covered  by  the  lowest  fibres  of  the  internal  oblique,  and 
when  they  are  divided  the  canal  is  laid  open  in  its  whole  length. 

The  Posterior  Wall  of  the  inguinal  canal  is  formed  by  the 
fascia  transversalis ;  medially,  however,  it  is  strengthened  by 
the  falx  inguinalis  (conjoined  tendon),  which  lies  in  front  of  the 
transversalis  fascia,  but  behind  the  cord  (Fig.  77). 

The  lowest  fibres  of  the  transversus  abdominis  lie  above  the 
level  of  the  lateral  part  of  the  canal,  and  in  consequence  its 
fleshy  fibres  take  no  part  in  the  formation  of  the  posterior  wall. 
Its  place  is  taken  by  the  fascia  transversalis,  which  descends 
beyond  the  lower  border  of  the  muscle  to  reach  the  inguinal 
ligament.  The  lower  fibres  of  the  internal  oblique  are  placed, 
at  their  origin,  in  front  of  the  spermatic  cord,  but  as  they  pass 
medially  they  arch  over  it — forming  the  Roof  of  the  canal — and 
then  descend  behind  it  in  the  falx  inguinalis  (conjoined  tendon). 


THE  ABDOMINAL  WALLS  255 

The  weakest  part  of  the  posterior  wall  of  the  canal  (the 
abdominal  inguinal  ring)  is  placed  opposite  the  strongest  part 
of  the  anterior  wall ;  similarly,  the  weakest  part  of  the  anterior 
wall  (the  subcutaneous  inguinal  ring)  is  'placed  opposite  the 
strongest  part  of  the  posterior  wall  (Fig.  77). 

The  Floor  of  the  canal  is  formed  by  the  upper  surface  of  the 
inguinal  ligament  and,  at  its  medial  end,  by  the  lacunar  ligament 
(of  Gimbernat). 

The  inferior  (deep)  epigastric  artery  arises  from  the  external 
iliac  as  it  lies  in  the  extra-peritoneal  fat  below  the  abdominal 
inguinal  (int.  abd.)  ring.  At  first  the  vessel  lies  below  the  ring, 
but  it  bends  upwards  and  medially  along  its  medial  border. 
This  relationship  is  of  importance  in  connection  with  the 
operation  for  strangulated  inguinal  hernia,  and  is  referred  to 
again  on  p.  263. 

Coverings  of  the  Testis  and  Spermatic  Cord. — In  its 
descent  (p.  257)  from  the  abdomen  to  the  scrotum,  the  testis 
traverses  the  inguinal  canal.  As  it  pushes  its  way  through  the 
transversalis  fascia  at  the  abdominal  inguinal  ring,  it  gains  for 
itself  and  the  spermatic  cord  a  sheath  of  this  fascia.  This 
covering  is  known  as  the  internal  spermatic  or  infundibuliform 
fascia.  The  testis  next  passes  under  cover  of  the  lower  border 
of  the  internal  oblique,  and  as  it  does  so,  it  drags  down  some 
fibres  of  the  muscle  to  form  the  cremaster.  In  the  child,  these 
fibres  can  be  traced  from  the  inguinal  ligament  and  the  lower 
border  of  the  internal  oblique  down  the  anterior  surface  of  the 
cord  and  up  its  posterior  surface  to  the  pubic  tubercle  (spine). 
Some  extend  to  the  testis,  while  others  only  pass  downwards  for 
a  short  distance  on  the  cord  before  looping  upwards  again. 
This  covering  lies  outside  the  internal  spermatic  fascia  and  is 
known  as  the  cremasteric  muscle  and  fascia.  The  contraction  of 
the  muscular  fibres  can  draw  the  testis  from  the  scrotum  up  to 
the  subcutaneous  inguinal  ring. 

On  passing  through  the  external  oblique  aponeurosis  at  the 
subcutaneous  inguinal  ring,  the  testis  gains  a  third  covering, 
the  external  spermatic  fascia. 

From  the  above  it  will  be  seen  that  the  testis  and  that  part 
of  the  spermatic  cord  which  lies  outside  the  inguinal  canal  have 
three  coverings.  In  the  medial  part  of  the  canal  the  spermatic 
cord  has  two  coverings,  and  in  the  lateral  part  only  one,  the 
internal  spermatic  fascia. 

The  Spermatic  Cord  can  be  examined  in  the  upper  part  of 


256 


THE  ABDOMEN  AND   PELVIS 


FIG.  77. — Sections  in  the  long  axis  of  the  Inguinal  Canal. 

1.  The  normal  condition,  showing  the  coverings  of  the  spermatic  cord. 

2.  Oblique  inguinal  hernia.     Note  the  relation  of  the  neck  of  the  hernial  sac  to  the 
inferior  epigastric  artery  and  observe  that  the  sac  descends  within  the  coverings  of  the 
spermatic  cord. 

3.  Direct  inguinal  hernia.     Note  the  relation  of  the  neck  of  the  hernial  sac  to  the 
inferior  epigastric  artery  and  observe  that  the  external  spermatic  (intercolumnar)  fascia  is 
the  only  covering  which  it  shares  with  the  spermatic  cord. 


THE  ABDOMINAL  WALLS  257 

the  scrotum,  and  as  it  lies  in  front  of  the  pubis  after  leaving 
the  subcutaneous  inguinal  ring.  Surrounded  by  its  coverings, 
it  lies  immediately  beneath  the  skin  and  the  two  layers  of 
superficial  fascia  (p.  240).  The  constituents  of  the  cord — (i) 
the  ductus  (vas)  deferens,  (2)  numerous  blood-vessels,  (3) 
lymphatics,  and  (4)  nerves — are  enclosed  in  the  three  coverings 
which  have  already  been  described. 

(1)  The  Ductus  Deferens  lies  posteriorly  in  the  cord  and  is 
surrounded  by  the  pampiniform  plexus  of  veins.     It  possesses 
a  small  lumen  and  a  very  thick  muscular  wall,  and  consequently 
can  easily  be  distinguished  when  the  spermatic  cord  is  examined. 
Its  artery  of  supply,  from  the  superior  vesical,  is  closely  applied 
to  the  duct. 

(2)  The  Pampiniform  Plexus  of  Veins  ascends  to  the  abdominal 
inguinal  (int.  abd.)  ring,  and  there  forms  the  spermatic  vein. 
The  External  Spermatic  (Cremasteric)  Artery  is  derived  from  the 
inferior  epigastric  -and  is  mainly  distributed  to  the  coverings. 
The  Internal  Spermatic  Artery,  a  branch  of  the  abdominal  aorta, 
descends  anteriorly  in  the  cord  and  supplies  the  testis  and 
epididymis. 

(3)  The  Lymphatics  ascend  from  the  testis  and  join  the 
lumbar  or  lateral  aortic  glands. 

(4)  The  External  Spermatic  Nerve  is  a  branch  of  the  genito- 
femoral  (genito-crural).    It  supplies  the  cremaster  muscle  and 
a  sensory  twig  to  the  tunica  vaginalis  (Mackenzie).    Numerous 
sympathetic  nerves  run  down  on  the  coat  of    the  internal 
spermatic  artery  from  the  aortic  plexus. 

During  attacks  of  renal  colic,  abnormal  stimuli  pass  from 
the  ureter  by  the  sympathetic  to  the  lower  thoracic  and  upper 
lumbar  segments.  As  a  result,  a  viscero-sensory  reflex  is 
established.  Pain  is  felt  in  the  loin  (p.  354)  and  shoots  down 
to  the  testis  (ext.  spermatic  nerve ;  L.  i  and  2),  but  does  not 
affect  the  overlying  skin  of  the  scrotum  (S.  2,  3,  and  4).  At  the 
same  time  a  viscero-motor  reflex  may  be  set  up,  and  the  resulting 
contraction  of  the  cremaster  muscle  (ext.  sperm,  nerve)  draws 
the  testis  up  towards  the  subcutaneous  inguinal  ring. 

Descent  of  the  Testis. — At  an  early  period  of  development 
the  testis  lies  at  the  brim  of  the  pelvis  near  the  abdominal 
inguinal  ring.  It  is  attached  to  the  lateral  wall  of  the  abdomen 
by  a  mesentery,  the  mesorchium,  and  is  connected  by  the 
gubernaculum  to  the  integument  which  forms  the  lowest  part 
of  the  scrotum.  This  cord  consists  of  condensed  mesoderm, 

17 


258 


THE  ABDOMEN  AND  PELVIS 


and  later  contains  numerous  unstriped  muscle  fibres.  It  is 
present  when  the  anterior  abdominal  wall  is  being  formed,  and 
the  muscles  have  to  accommodate  themselves  so  as  to  enclose 
it  in  the  inguinal  canal.  At  the  same  time  the  umbilical  arteries, 
which  lie  medial  to  the  testis,  lift  up  a  peritoneal  fold  so  that 
the  gland  projects  into  a  small  peritoneal  fossa.  Until  the 
seventh  month  this  fossa  lies  opposite  the  abdominal  inguinal 


FiG.  78. — Diagrams  to  illustrate  the  Different  Conditions  of  the 
Processus  Vaginalis. 

a.  Foetal  condition,  showing  completely  patent  processus  vaginalis. 

b.  Normal  condition,  with  obliterated  processus  vaginalis  and  patent  tunica  vaginalis 
testis. 

c.  d.  The  processus  is  only  partially  obliterated. 
e.  The  closure  of  the  processus  has  been  oblique. 

f.  The  funicular  part  of  the  process  is  shut  off  from  the  tunica  vaginalis  and  repeated 
attempts  at  obliteration  have  led  to  the  valve-like  constrictions. 

f.  Encysted  hydrocele  of  the  spermatic  cord. 
.  As  g,  but  the  proximal  part  of  the  processus  is  patent. 
/.    As  h,  but  a  hydrocele  is  present  in  the  tunica  vaginalis. 
k.  Hydrocele  of  the  tunica  vaginalis. 

/.     One  variety  of  encysted  hernia,  in  which  the  closed  abdominal  end  of  the  processus 
vaginalis  has  been  invaginated  within  the  partially  patent  funicular  part  of  the  processus. 
m.  As  I},  with,  in  addition,  the  sac  of  an  acquired  inguinal  hernia. 

ring,  but  during  the  eighth  month  it  invades  the  inguinal  canal. 
At  the  same  time  it  becomes  elongated  and  forms  the  processus 
vaginalis.  Thereafter  the  testis  enters  the  inguinal  canal,  and  it 
gains  its  permanent  scrotal  position  during  the  ninth  month.  The 
part  of  the  processus  which  is  related  to  the  spermatic  cord  loses 
its  connection  with  the  general  peritoneal  cavity  and  becomes 
converted  into  a  solid  cord.  The  lower  part  of  the  processus 
remains  patent  and  constitutes  the  tunica  vaginalis  (p.  265). 
Congenital  Anomalies. — In  Ectopia  Testis  the  guber- 


THE  ABDOMINAL  WALLS  259 

naculum  has  failed  to  acquire  its  connection  with  the  bottom 
of  the  scrotum,,  but  instead  has  become  attached  to  the  skin 
of  the  region  in  which  the  testis  is  found.  It  may  lie  in  the 
perineum,  in  the  groin,  or  near  the  anterior  superior  iliac  spine, 
but  it  always  maintains  its  normal  relation  to  the  processus 
vaginalis,  which  is  also  misplaced. 

Congenital  Inguinal  Hernia ;  Congenital  Hydrocele. — 
Numerous  developmental  errors  may  occur  in  connection  with 
the  closure  of  the  processus  vaginalis.  All  the  congenital 
varieties  of  inguinal  hernia  and  of  hydrocele  result  from  such 
errors.  In  Fig.  78  (b)  the  normal  condition  is  depicted.  The 
processus  remains  patent  below  as  the  tunica  vaginalis  testis, 
but  above  it  is  represented  by  a  fibrous  cord.  In  (a)  the 
processus  remains  patent  throughout,  i.e.  a  persistence  of  the 
fcetal  condition.  If  the  opening  at  the  neck  is  sufficiently  wide, 
bowel  or  omentum  will  enter  the  sac  and  pass  down  to  its  lower 
end.  It  will  then  be  in  close  contact  with  the  testis  and  only 
separated  from  it  by  the  visceral  layer  of  the  patent  tunica 
vaginalis  (vaginal  type  of  oblique  inguinal  hernia).  If  the 
opening  at  the  neck  is  too  small  to  permit  .the  passage  of  a 
hernia,  serous  fluid  from  the  peritoneal  cavity  may  find  its  way 
into  the  sac  and  give  rise  to  an  Intermittent  Hydrocele.  The 
condition  is  not  always  present,  as  when  the  child  lies  down 
the  fluid  passes  back  into  the  general  peritoneal  cavity.  Owing 
to  this  intermittent  character,  it  may  be  mistaken  for  a  hernia. 
Further,  it  may  be  confused  with  a  hydrocele  of  the  cord  or  of 
the  tunica  vaginalis,  because  it  cannot  be  reduced  by  taxis. 

In  (c)  the  tunica  vaginalis  has  been  shut  off,  but  the  proximal 
part  of  the  processus  remains  patent  and  maintains  its  connection 
with  the  general  peritoneal  cavity.  This  condition  gives  rise  to 
the  Funicular  Type  of  Oblique  Inguinal  Hernia,  which  constitutes 
95  per  cent  (Stiles)  of  all  congenital  herniae.  If  the  neck  is  not 
large  enough  to  admit  a  hernia,  an  intermittent  hydrocele  of 
the  funicular  type  may  occur.  The  conditions  shown  in  (d) 
and  (e)  are  very  similar.  The  tunica  vaginalis  is  closed  above, 
and  the  proximal  part  of  the  processus  remains  patent.  In 
both,  but  more  especially  in  (e)}  the  line  of  closure  has  been 
oblique  and  not  horizontal  as  in  (c).  In  order  to  open  the  sac 
of  a  hernia  of  the  funicular  type  affecting  (e)}  three  layers  of 
peritoneum  must  be  incised.  This  variety  was  formerly  ex- 
plained as  an  acquired  hernia  descending  behind  a  partially 
closed  processus  vaginalis. 

17  a 


260 


THE  ABDOMEN  AND  PELVIS 


The  processus  may  be  shut  off  from  the  tunica  vaginalis 
below,  and  from  the  general  peritoneal  cavity  above,  but  yet 
remain  patent  in  its  intermediate  part  (g).  Should  this  sac 
become  distended  with  serous  fluid,  it  will  form  an  Encysted 
Hydrocele  of  the  Cord.  A  similar  variety  is  shown  in  (h).  The 
processus  has  been  obliterated  in  two  areas,  but  the  patent 
portions  are  so  arranged  that  the  occurrence  of  a  funicular 
hernia,  an  encysted  hydrocele  of  the  cord,  and  a  hydrocele  of  the 

tunica      vaginalis 
testis  at  one  and 
the  same  time  is 
quite  possible  (i). 
In  (I)  an  acquired 
hernia    is    shown 
invaginating      an 
encysted     hydro- 
cele, a  condition  which  can  only 
occur  when  there  is  little  fluid 
in  the  hydrocele  ;  in  (m)  it  is 
seen  passing  down  posteriorly. 
In  cases  of  imperfect  descent  of  the 
testis    the    processus    vaginalis    rarely 
reaches  the  upper  part  of  the  scrotum 
and  never  extends  down  into  it.    When 
the  testis  is  retained  within  the  inguinal 
canal  at  the  subcutaneous  inguinal  ring, 
FIG.  79.— Diagram  of  In-    the  processus  js  near]y  always  patent, 

and  should  bowel  or  omentum  descend 
into  it,  the  commonest  type  (inter- 
parietal)  of  interstitial  hernia  is  produced 

abdominal'waTl  have  been     C^g-  79)'       The  neck  of  the  SOC  lies  at 

removed.     The    patent    the  abdominal   inguinal   ring,   and   its 
processus  vaginalis  and    fundus  lies  between  the  external  oblique 

the  peritoneum  are  shown  .  .       .  .  . . n 

in  biue>  aponeurosis   and   the   internal   oblique 

muscle.     The  hernia  may  enlarge  in  the 

region  of  the  abdominal  inguinal  ring  and  give  rise  to  a  dilata- 
tion of  the  sac,  just  beyond  its  neck.  This  enlargement  lies  be- 
tween the  fascia  transversalis  and  the  peritoneum,  and  is  known 
as  a  pro-peritoneal  hernia.  In  this  case  it  is  associated  with  the 
interstitial  interparietal  form.  The  whole  hernia  is  dumb-bell 
shaped,  the  constriction  being  placed  at  the  abdominal  inguinal 
(int.  abd.)  ring. 


guinal  Canal  to  show  the 
Position  of  an  Inter- 
parietal  Interstitial 
Hernia.  Portions  of  the 
different  layers  of  the 


THE  ABDOMINAL  WALLS 


261 


If  the  testis  with  its  patent  processus  emerges  from  the 
inguinal  canal  but  fails  to  descend  into  the  scrotum,,  a  superficial 
inguinal  hernia  may  result.  In  these  cases  the  sac  is  often 
bilocular,  the  one  enlargement  being  situated  under  the  skin 
and  the  other  in  the  inguinal  canal.  Occasionally  the  sac  of  an 
inguinal  hernia  not  only  extends  into  the  scrotum  but  possesses 
a  second  loculus  either  just  outside  or  within  the  inguinal  canal. 

An   Acquired    Oblique    Hernia   enters  the  inguinal  canal 
at  the  abdominal  inguinal  ring  and  makes  its  way  down  into 
the    scrotum    inside  the  spermatic  cord  (Fig.   77).     The  con- 
stituents   of     the 
cord    are    spread 
out  over  the  sur- 
face of  the  sac  and 
the  ductus  defer- 
ens  is  always  found 
on    its     posterior 
aspect. 

Inguinal  Her- 
nia: Radical  Cure. 
— The  Incision  for 
inguinal  hernia  is 
made  along  the 
medial  half  or  two- 
thirds  of  the  line 
joining  the  anterior 
superior  iliac  spine 
to  the  root  of  the 

penis,  and  should  expose,  in  its  lateral 
part;  the  aponeurosis  of  the  external 
oblique.  The  fasciae  of  Camper  and 
Scarpa  (p.  240)  and  the  superficial  epigastric  and  external  pudic 
arteries,  which  lie  between  them,  are  divided.  At  the  medial 
part  of  the  wound  the  spermatic  cord  is  exposed  and  the  surgeon 
can  at  once  define  the  subcutaneous  inguinal  ring.  The  cord  is 
freed  and  lifted  up  to  the  surface,  dragging  the  testis  upwards 
in  the  scrotum.  In  order  to  avoid  injuring  the  ductus  deferens, 
forceps  are  carefully  applied  to  the  margins  of  the  cord,  which  is 
put  on  the  stretch  downwards  and  medially  (Stiles).  The  external 
spermatic  fascia  (p.  255)  is  very  thin,  and  the  muscular  fibres  of 
the  cremaster,  which  are  very  well  marked  in  the  male  infant, 
are  visible  through  it.  These  two  layers  are  carefully  stripped  off 


M 

i 

h 

CD 

i 

X 

ij 

w 

u 

2 

D 

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(/) 

V) 

i/) 

K 

Z 

Z 

(t 

UJ 

V- 

0 

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o 

i/l 

0 

Q 

• 

Q 
00 

Z 
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u. 

J 

j 

•A 

v- 

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0 

^«cx 

°» 

FIG.  80. — Diagram  of  the  In- 
guinal Canal  to  show  the 
Position  of  an  Extra- parietal 
Interstitial  Hernia.  Portions 
of  the  different  layers  of  the 
abdominal  wall  have  been 
removed.  The  patent  pro- 
cessus vaginalis  and  the  peri- 
toneum are  shown  in  blue. 


262  THE  ABDOMEN  AND  PELVIS 

after  they  have  been  divided  in  the  long  axis  of  the  cord.  The 
veins  of  the  pampiniform  plexus  and  the  internal  spermatic 
artery  can  now  be  seen  on  the  anterior  surface  of  the  sac,  but 
before  they  can  be  separated  from  it,  the  internal  spermatic 
(infundibuliform)  fascia  (p.  255)  must  be  incised  and  stripped  off. 
If  this  is  not  done,  difficulty  will  be  experienced  in  separating 
the  vessels  without  injuring  them.  At  the  same  time  the 
remaining  veins  and  the  ductus  deferens  should  be  freed  from 
the  posterior  aspect  of  the  sac.  The  neck  of  the  sac  is  carefully 
isolated,  ligated,  and  divided.  It  may  be  allowed  to  retract 
into  the  abdomen  or  may  be  transplanted  up  the  canal  towards 
the  anterior  superior  iliac  spine.  The  rest  of  the  sac  is  removed, 
but,  if  it  is  of  the  vaginal  type  (Fig.  78  (#)),  the  lower  part  may 
be  stitched  up  to  form  a  closed  tunica  vaginalis  testis. 

The  same  approach  and  method  of  dividing  the  coverings 
of  the  cord  are  employed  in  such  conditions  as  varicocele  (p.  264), 
hydrocele  of  the  cord,  and  hydrocele  of  the  tunica  vaginalis. 

In  infants  or  young  people  where  the  hernia  is  due  to  the 
presence  of  a  preformed  sac  and  not  to  any  inherent  weakness 
of  the  abdominal  wall,  the  condition  may  be  completely  cured 
by  the  removal  of  the  sac,  but  it  is  sometimes  advisable  to  insert 
one  or  two  stitches  to  narrow  the  subcutaneous  inguinal  ring  or 
to  approximate  the  falx  inguinalis  (conjoined  tendon)  to  the 
inguinal  ligament. 

In  elderly  patients  it  is  necessary  to  strengthen  the  weak 
area  in  the  abdominal  wall  which  has  predisposed  them  to 
hernia.  The  external  oblique  aponeurosis  is  split  up  along 
the  course  of  the  canal  and  the  lower  borders  of  the  internal 
oblique  and  the  falx  inguinalis  are  denned.  A  few  mattress 
sutures  may  now  be  passed  through  the  deep  surface  of  the 
thickened  lower  portion  of  the  external  oblique  aponeurosis, 
which  is  forming  the  inguinal  ligament,  and  up  through  the  falx 
inguinalis  so  as  to  drag  the  latter  structure  downwards  behind 
the  former.  The  close  relationship  of  the  femoral  vessels  to  the 
inguinal  ligament  must  be  borne  in  mind  when  these  sutures 
are  inserted.  In  this  way  the  posterior  wall  of  the  inguinal 
canal  is  greatly  strengthened.  A  similar  effect  can  be  produced 
in  the  anterior  wall  by  uniting  the  two  portions  of  the  external 
oblique  in  such  a  way  that  they  overlap. 

When  sutures  are  being  passed  through  the  posterior  wall 
of  the  canal  in  the  neighbourhood  of  the  abdominal  inguinal 
(int.  abd.)  ring,  the  inferior  epigastric  vessels  must  be  carefully 


THE  ABDOMINAL  WALLS  263 

avoided.  In  all  cases  where  the  canal  is  artificially  narrowed, 
the  surgeon  must  guard  against  closing  it  too  tightly  lest  undue 
pressure  be  exerted  on  the  spermatic  cord. 

Oblique  inguinal  hernia  of  long  duration  and  great  size  tends 
to  take  a  more  and  more  direct  course  through  the  abdominal 
wall.  The  neck  of  the  hernia  gradually  enlarges  the  abdominal 
inguinal  ring  downwards  and  medially,  until  it  comes  to  lie 
directly  behind  the  subcutaneous  inguinal  ring.  In  these  cases, 
after  the  hernia  has  been  reduced,  the  examining  ringer  can  be 
passed  directly  backwards  through  the  abdominal  wall  into  the 
abdomen.  This  alteration  in  the  direction  of  the  inguinal  canal 
is  necessarily  accompanied  by  an  alteration  in  the  direction 
taken  by  the  inferior  epigastric  artery.  It  now  passes  medially 
to  the  pubic  tubercle  (spine)  and  then  ascends  behind  the  lateral 
border  of  the  rectus  abdominis. 

Direct  Inguinal  Hernia. — In  the  lower  part  of  the  anterior 
abdominal  wall  the  Triangle  of  Hesselbach  can  be  identified. 
Its  base  is  formed  by  the  medial  end  of  the  inguinal  ligament, 
its  medial  side  by  the  lateral  border  of  the  rectus  abdominis, 
and  its  lateral  side  by  the  inferior  epigastric  artery,  which 
separates  the  triangle  from  the  abdominal  inguinal  ring. 
Occasionally,  hernia  occurs  through  the  fascia  transversalis  in 
the  floor  of  Hesselbach's  triangle.  This  variety,  known  as 
a  Direct  (or  Internal}  Hernia,  enters  the  inguinal  canal  at  its 
medial  end  arid  immediately  opposite  the  subcutaneous  inguinal 
(ext.  abd.)  ring.  In  doing  so,  it  usually  passes  directly  through 
the  falx  inguinalis  (conjoined  tendon),  though  it  may  appear  at 
its  lateral  margin.  Its  subsequent  course  is  the  same  as  that  of 
an  oblique  hernia.  The  most  important  difference  between 
these  two  varieties  (the  direct  and  the  oblique)  lies  in  their 
relationship  to  the  inferior  epigastric  artery.  The  neck  of  the 
sac  of  an  oblique  hernia  is  placed  lateral  to  the  artery,  while 
the  neck  of  the  sac  of  a  direct  hernia  is  medial  to  the  vessel 

(Fig.  77)- 

In  a  case  of  old-standing  inguinal  hernia  some  difficulty 
may  be  experienced  in  deciding  which  of  the  two  varieties  is 
present,  as  in  both  cases  the  hernial  opening  is  large  and  the 
exploring  ringer  will  pass  directly  through  the  abdominal  wall. 
Should  such  a  hernia  become  strangulated,  the  surgeon  will  be 
well  advised  to  incise  the  constricting  neck  of  the  sac  in  an 
upward  and  medial  direction,  in  order  to  avoid  the  inferior 
epigastric  vessels.  For  if  he  mistakes  a  direct  for  an  oblique 


264  THE  ABDOMEN  AND  PELVIS 

hernia  and  incises  the  neck  of  the  sac  in  a  lateral  direction,  the 
vessels  will  be  wounded  ;  or  if  he  mistakes  an  old-standing 
oblique  for  a  direct  hernia  and  cuts  in  a  medial  direction,  the 
same  accident  will  occur. 

The  incision  for  direct  hernia  is  practically  the  same  as  that 
employed  in  dealing  with  the  oblique  variety  (p.  261),  but  the 
coverings  of  the  sac  are  somewhat  different.  After  the  external 
spermatic  fascia  has  been  divided,  the  spermatic  cord  within 
its  cremasteric  and  infundibuliform  fasciae  is  found  lying  to 
the  lateral  side,  and  the  hernia,  covered  by  a  thin  expansion 
from  the  falx  inguinalis  (conjoined  tendon),  to  the  medial  side. 
When  this  layer  is  incised  the  hernial  sac  is  exposed  covered  by 
a  sheath  which,  though  derived  from  the  fascia  transversalis, 
is  quite  distinct  from  the  internal  spermatic  (infundibuliform) 
fascia  of  the  cord  (Fig.  77). 

In  the  female,  the  inguinal  canal  is  occupied  by  the  round 
ligament  of  the  uterus,  which  is  attached  to  the  skin  and  fascia 
of  the  labium  majus.  In  the  foetus,  it  also  lodges  a  peritoneal 
process,  the  Canal  of  Nuck,  which  corresponds  to  the  processus 
vaginalis  in  the  male.  At  birth,  the  canal  of  Nuck  should  be 
completely  closed,  but  it  may  remain  patent  and  give  rise  to 
inguinal  hernia.  This  condition  occurs  rarely  in  adult  women, 
but  is  not  uncommon  in  female  infants  and  young  girls.  As 
the  hernia  increases  in  size  it  drags  into  its  wall  a  part  of  the 
suspensory  ligament  of  the  ovary  (p.  387),  which,  at  its  lateral 
extremity,  is  not  far  distant  from  the  abdominal  inguinal  ring. 
As  a  result  the  ovary  and  the  distal  part  of  the  uterine  (Fallopian) 
tube  are  often  found  in  the  sac. 

Imperfect  closure  of  the  canal  of  Nuck  may  lead  to  encysted 
hydrocele  of  the  round  ligament. 

Varicocele  is  a  varicose  condition  of  the  veins  of  the 
pampiniform  plexus  (p.  257).  In  adolescents  it  is  almost 
invariably  on  the  left  side,  and  many  explanations  have  been 
suggested,  (a)  The  left  spermatic  vein,  which  is  formed  by  the 
union  of  the  pampiniform  veins,  joins  the  left  renal  almost  at 
right  angles,  whereas  the  right  spermatic  vein  joins  the  inferior 
vena  cava  very  obliquely.  It  has  been  urged  that,  owing  to  its 
method  of  termination,  the  outflow  from  the  spermatic  vein  is 
not  so  free  on  the  left  side  as  it  is  on  the  right,  (b)  The  total 
length  of  the  spermatic  vein  and  pampiniform  plexus  is  less 
on  the  right  side  than  the  left,  since  the  left  testis  hangs  lower 
in  the  scrotum  and  the  left  spermatic  vein  terminates  at  a  higher 


THE  ABDOMINAL  WALLS  265 

level,  (c)  The  valve  at  the  orifice  of  the  left  spermatic  vein 
may  be  absent,  (d)  The  venous  return  from  the  left  spermatic 
vein  may  be  obstructed  by  the  pressure  of  the  iliac  colon,  behind 
which  it  passes  as  it  ascends  on  the  iliacus  (Fig.  88). 

A  varicocele  on  the  right  side  generally  indicates  that  the 
right  spermatic  vein  is  pressed  on  by  some  tumour  growth. 

In  this  condition  the  veins  of  the  plexus  are  much  enlarged 
and  very  tortuous,  and,  when  they  have  been  exposed  (p.  262), 
they  must  be  separated  from  the  ductus  (vas)  deferens.  The 
vessels  are  then  ligated  above  and  below  and  the  intervening 
portion  is  removed.  The  ligated  ends  are  then  tied  together 
and  the  coverings  of  the  cord  are  united  over  them.  In  the 
process  the  internal  spermatic  artery  is  not  uncommonly 
resected,  but  the  testis  receives  a  sufficient  supply  from  the 
artery  to  the  ductus  deferens,  which  becomes  increased  in  size. 

Undescended  Testis  (see  also  p.  258). — In  embedding  an 
imperfectly  descended  testis  in  the  scrotum,  the  preliminary 
steps  are  much  the  same  as  in  the  operation  for  varicocele,  but 
the  external  oblique  aponeurosis  may  have  to  be  slit  up  from 
the  subcutaneous  inguinal  ring.  It  is  generally  found  that  the 
ductus  deferens  is  sufficiently  long  to  allow  the  testis  to  be 
placed  at  the  bottom  of  the  scrotum,  but  it  will  be  necessary  to 
divide  all  the  other  constituents  of  the  cord,  together  with  its 
coverings.  As  the  testis  increases  in  size  about  puberty, 
operative  interference  should  be  undertaken  a  year  or  two 
before  that  period  in  order  that  the  circulation,  temporarily 
disturbed  by  the  division  of  the  internal  spermatic  artery,  may 
be  completely  and  efficiently  re-established  for  the  nutrition  of 
the  growing  organ. 

The  Testis  lies  obliquely  in  the  scrotum  so  that  the  upper 
pole  is  antero-lateral  to  the  lower,  and  the  Epididymis  is 
closely  applied  to  the  lateral  aspect  of  its  posterior  border. 
Inside  its  fascial  coverings  (p.  255)  the  testis  is  invested  by  a 
closed  peritoneal  sac,  the  Tunica  Vaginalis.  This  sac  possesses 
a  parietal  layer,  associated  with  the  coverings  (Fig.  81),  and  a 
visceral  layer,  which  covers  the  testis  anteriorly,  medially,  and 
laterally,  but  not  posteriorly.  The  epididymis  obtains  a  partial 
covering  from  the  visceral  layer,  and  the  medial  aspect  of  its 
body  is  separated  from  the  postero-lateral  aspect  of  the  testis 
by  a  small  peritoneal  recess — the  sinus  epididymidis  (digital 
fossa).  In  large  hydroceles  this  fossa  may  become  so  deep  as 
to  separate  the  two  structures  completely.  Above  the  testis 


266 


THE  ABDOMEN  AND  PELVIS 


the  tunica  vaginalis  extends  upwards  for  a  short  distance  on  the 
spermatic  cord. 

The  testis  possesses  a  capsule  of  connective  tissue  which  is  known  as  the 
Tunica  Albuginea  (Fig.  81).  Anteriorly  and  on  each  side  it  blends  with  the 
visceral  layer  of  the  tunica  vaginalis  ;  posteriorly,  where  it  is  in  relation  to 
the  epididymis  and  ductus  (vas)  deferens,  it  is  greatly  thickened  to  form  the 
Mediastinum  Testis,  which  sends  numerous  septa  into  the  body  of  the  testis 
to  join  the  tunica  albuginea.  In  this  way  the  organ  is  subdivided  into 
lobules  and  these  contain  the  Seminiferous  Tubules.  The  blood-vessels  break 
up  into  capillaries  on  the  deep  surface  of  the  tunica  albuginea  and  on  the  sides 
of  the  septa. 

Hernial  sac  formed  by 
funicular  process 

Serous  coat  of  gut 


External  spermatic 
fascia 


\  Cremasteric  fascia 


Internal  spermatic 
fascia 


Tunica  vaginalis 
testis 


Sinus  of  epididymis 
Body  of  epididymis 


FIG.  8 1. — Diagram  of  a  Transverse  Section  through  the  Scrotum  and  Testes. 

A  shows  the  peritoneal  relationships  of  the  vaginal  type  of  developmental  inguinal  hernia. 

B  shows  the  peritoneal  relationships  of  the  funicular  type  of  developmental  inguinal 
hernia. 

A  corresponds  to  Fig.  78(0),  and  B  corresponds  to  an  exaggerated  condition  of 
Fig.  78  (if). 

In  Excision  of  the  Testis  two  routes  are  available.  The 
testis  may  be  approached  from  below  by  incising  the  scrotum, 
or  the  spermatic  cord  may  be  exposed  above,  as  in  the  operation 
for  varicocele,  and,  by  traction  on  it,  the  testis  may  be  dragged 
up  out  of  the  scrotum  into  the  wound.  The  latter  method  is 
preferable  in  malignant  disease,  as  it  enables  the  surgeon  to 
remove  the  testis,  the  spermatic  cord,  and  the  associated 
lymphatics  through  the  same  incision.  This  route  is  also  used 
in  tuberculous  disease  of  the  testis  when  there  are  no  sinuses  or 
adhesions  to  the  scrotum.  If  the  latter  conditions  are  present,  the 
lower  route  is  adopted  and  the  incision  is  planned  so  as  to  excise 
the  involved  skin  area.  This  method  provides  excellent  drainage. 


THE  ABDOMINAL  WALLS  267 

The  Epididymis  begins  in  an  enlargement  which  is  situated 
on  the  upper  pole  of  the  testis.  This  is  termed  the  Head  (globus 
major),  and  it  receives  the  efferent  ducts  of  the  testis,  which 
unite  to  form  the  convoluted  Ducts  of  the  Epididymis.  The 
body,  which  contains  the  downward  continuation  of  the  duct, 
is  much  narrower  than  the  head,  and  is  closely  applied  to  the 
lateral  aspect  of  the  posterior  border  of  the  testis  (Fig.  81). 
Interiorly,  the  epididymis  again  enlarges  to  form  the  Tail 
(globus  minor},  and  from  its  medial  side  the  duct  emerges  as 
the  ductus  (vas)  defer  ens,  with  greatly  thickened  walls.  This 
structure  ascends  along  the  medial  side  of  the  epididymis  and 
is  closely  related  to  the  terminal  branches  of  the  internal 
spermatic  artery.  At  the  upper  pole  of  the  testis  the  ductus 
deferens  enters  the  spermatic  cord. 

Development  of  the  Testis  and  Epididymis. — Prior  to  the  develop- 
ment of  the  permanent  kidneys,  the  embryo  possesses  two  primitive  kidneys, 
the  Wolffian  bodies,  which  communicate  with  the  cloaca  by  the  Wolffian 
ducts.  The  testis  develops  in  close  relation  to  the  Wolffian  body,  and,  as  the 
Wolffian  body  atrophies,  the  efferent  ducts  of  the  testis  become  connected 
to  the  Wolffian  duct,  which  forms  both  the  epididymis  and  the  ductus  deferens 
(p.  394).  Most  of  the  tubules  of  the  Wolffian  body  disappear  and  the  few 
which  persist  constitute  the  Paradidymis  or  Organ  of  Giraldes,  which  is 
situated  in  the  lower  part  of  the  spermatic  cord,  just  above  the  head  of  the 
epididymis.  The  Mullerian  ducts,  which  play  such  an  important  part  in  the 
formation  of  the  female  generative  organs  (p.  394),  disappear  almost  entirely 
in  the  male.  Each  is  represented  by  two  Appendices  Testis  (the  Hydatids  of 
Morgagni),  which  lie  at  the  upper  pole  of  the  testis  just  in  front  of  the  epi- 
didymis. Both  the  paradidymis  and  the  appendices  testis  may  give  rise  to 
cysts,  which  frequently  contain  spermatozoa  and  are  termed  spermatoceles. 
The  prostatic  utricle  (sinus  pocularis)  represents  the  fused  caudal  ends  of  the 
two  Mullerian  ducts. 

In  Hydrocele  of  the  tunica  vaginalis,  fluid  collects  in  the 
sac  and  gradually  distends  it  above,  in  front,  and  on  each  side 
of  the  testis,  giving  rise  to  a  somewhat  egg-shaped  swelling. 
The  testis  and  epididymis  lie  posterior  to  it,  but  in  rare  cases 
inversion  of  the  testis  may  be  present.  In  this  condition  the 
epididymis  is  related  to  the  anterior  border  and  the  tunica 
vaginalis  to  the  posterior  border  and  lateral  surfaces  of  the 
testis,  while  the  ductus  deferens  occupies  an  anterior  position 
in  the  cord  (Treves).  Before  tapping  a  hydrocele  it  is  important 
to  determine  the  position  of  the  testis  with  reference  to  the 
swelling.  The  trochar  and  cannula  are  pushed  through  the 
skin  of  the  scrotum  anteriorly  in  an  upward  and  backward 
direction.  The  distended  tunica  vaginalis  is  pierced  from  in 
front  (to  avoid  the  testis)  and  near  its  lower  pole  (to  facilitate 
the  evacuation  of  its  contents).  Care  must  be  taken  not  to 


268  THE  ABDOMEN  AND  PELVIS 

injure  any  of  the  superficial  veins,  as  their  dependent  position 
and  the  relief  of  tension  following  the  operation  may  tend  to 
increase  the  amount  of  haemorrhage. 

In  the  radical  cure  of  a  hydrocele  the  approach  is  very  similar 
to  that  employed  in  varicocele  (p.  262).  The  hydrocele  is 
pushed  upwards  into  the  wound,  and  the  coverings  are  incised 
and  dissected  off.  The  parietal  layer  of  the  tunica  vaginalis  is 
cut  away  along  the  lines  of  its  reflection  on  to  the  testis  and 
epididymis,  or  a  vertical  incision  may  be  made  in  the  tunica 
vaginalis  anteriorly,  and  the  two  halves  may  then  be  folded  back- 
wards so  that  their  edges  can  be  united  behind  the  epididymis. 

Examination  of  the  Testis  and  Spermatic  Cord. — The 
shape  and  consistence  of  the  testis  can  readily  be  appreciated 
when  it  is  examined  in  situ,  and  any  alteration  of  the  normal 
elastic  feel,  or  variation  in  size  or  shape,  should  be  carefully 
observed.  The  epididymis  can  be  felt  along  the  postero-lateral 
border.  Although  it  is  usually  fixed  in  position,  the  epididymis 
can  sometimes  be  moved  independently  of  the  testis  and  yet 
may  be  otherwise  normal. 

Enlargement  of  the  tail  (globus  minor)  of  the  epididymis  is 
not  uncommonly  associated  with  a  bacterial  infection  ascending 
along  the  ductus  deferens  from  the  urethra,  such  as  occurs  in 
gonorrhoea.  Tuberculous  disease,  on  the  other  hand,  usually 
commences  in  the  head  (globus  major),  as  the  infection  is  carried 
by  the  blood  stream,  and  the  bacilli  settle  down  in  the  area 
supplied  by  the  epididymal  branches  of  the  internal  spermatic 
artery. 

When  acutely  inflamed,  the  epididymis  becomes  sausage- 
shaped.  It  is  greatly  swollen  and  tends  to  surround  the  posterior 
part  of  the  testis,  which,  though  also  enlarged,  is  rather  obscured. 
On  the  other  hand,  in  acute  inflammatory  conditions  of  the 
testis,  the  swelling  resembles  a  Jaffa  orange  in  shape,  and  the 
epididymis  cannot  be  easily  defined.  Both  these  conditions 
may  be  somewhat  masked  by  an  associated  acute  hydrocele. 

The  ductus  deferens  can  be  felt  along  the  postero-medial 
border  of  the  testis  and  may  easily  be  distinguished  in  the 
spermatic  cord  owing  to  its  thick  muscular  wall.  In  tuberculous 
disease,  the  duct  is  often  irregularly  thickened  and  its  recognition 
is  still  easier ;  in  varicocele,  on  the  other  hand,  the  increased 
number  and  size  of  the  veins  may  render  its  identification  more 
difficult.  The  presence  of  a  hernial  sac  may  be  made  out  by 
grasping  the  spermatic  cord  and  allowing  the  individual  structures 


THE  ABDOMINAL  WALLS  269 

to  slip  away  from  between  the  finger  and  thumb.  If  both  cords 
are  examined  at  the  same  time,,  the  presence  of  an  additional 
structure  on  the  affected  side  can  often  be  determined. 

In  children,  the  cremasteric  muscle  may  be  so  strongly 
developed  that  it  is  able  to  draw  the  testis  up  into  the  inguinal 
canal.  The  sudden  disappearance  from  the  scrotum  of  a  lump 
which  may  as  suddenly  reappear  may  lead  the  mother  to  suppose 
that  the  child  is  suffering  from  a  rupture,  whereas  the  swelling 
is  simply  the  testis.  Similarly,  the  condition  of  undescended 
testicle  may  be  mistaken  for  a  rupture,  if  the  mother  fails  to 
notice  the  absence  of  the  testis  from  the  scrotum  on  the  affected 
side.  Examination  of  the  mobility  of  the  testis  can  be  carried 
out  by  testing  the  cremasteric  reflex.  Gentle  stroking  of  the 
skin  over  the  proximal  part  of  the  front  of  the  thigh  stimulates 
the  sensory  branches  of  the  genito-femoral  (genito-crural)  nerve 
and  causes  a  reflex  contraction  of  the  cremaster,  which  is  supplied 
by  the  motor  part  of  the  same  nerve. 

Posterior  Abdominal  Wall.  —  The  Lumbo  -  dorsal 
(Lumbar)  Fascia  is  a  strong  aponeurotic  layer  which  extends 
between  the  ribs  and  the  iliac  crest.  Laterally  it  gives  origin 
to  the  internal  oblique  and  the  transversus.  Medially  it  splits 
into  three  lamellae.  Of  these,  the  posterior  reaches  the  lumbar 
spines,  and  the  middle  the  tips  of  the  transverse  processes. 
They  enclose  between  them  the  large  sacro-spinalis  (erector 
spinse)  muscle.  The  anterior  lamella  is  attached  to  the  bases 
of  the  transverse  processes  ;  between  it  and  the  middle  lamella 
the  quadratus  lumborum  is  situated  (Fig.  82). 

The  posterior  lamella  of  the  lumbo-dorsal  fascia  is  covered 
by  the  latissimus  dorsi,  to  which  it  partly  gives  origin.  The 
lateral  margin  of  this  muscle  crosses  the  free  posterior  border 
of  the  external  oblique,  and,  together  with  a  portion  of  the 
iliac  crest,  they  enclose  the  lumbar  triangle  of  Petit.  The  roof 
of  this  triangle  is  formed  by  the  deep  fascia  of  the  back,  and  its 
floor  by  the  internal  oblique  (Fig.  74). 

The  upper  lumbar  triangle  lies  under  cover  of  the  latissimus 
dorsi,  above  and  to  the  medial  side  of  the  lumbar  triangle  of 
Petit.  It  is  bounded  above  by  the  twelfth  rib  ;  medially,  by 
the  lateral  margin  of  the  sacro-spinalis  ;  below,  by  the  line  of 
origin  of  the  internal  oblique  from  the  lumbo-dorsal  fascia, 
which  corresponds  to  the  lower  border  of  the  latissimus  dorsi. 
The  floor  of  this  space  is  formed  by  the  lumbo-dorsal  fascia, 
and  constitutes  the  weakest  part  of  the  posterior  abdominal  wall. 


270 


THE  ABDOMEN  AND  PELVIS 


Abscesses  arising  in  connection  with  the  vertebral  column  lie 
between  the  fascial  envelope  of  the  abdomen  (p.  271)  and  the 
lumbo-dorsal  fascia  (Fig.  83).  If  the  pus  bursts  through  the 
latter  layer,  it  enters  the  upper  lumbar  triangle  and  then  passes 
downwards  and  laterally.  Escaping  from  under  cover  of  the 
latissimus  dorsi,  it  gains  the  lumbar  triangle  (of  Petit)  and  points 
above  the  iliac  crest. 


Linea  alba 


Rectus  sheath,  ant.  wall 

Rectus  sheath,  post,  wall 
Transversalis  fascia 

Peritoneum 


Duodenum,  third  part 
Ascending  colon 


I'eri-nephric 
fascia 


Lumbo-dorsal 
fascia 


Peri-nephric  abscess 

Lumbo-dorsal  f.,  ant.  layer 
Lumbo-dorsal  f.,  middle  layer 
Lumbo-dorsal  f.,  post,  layer 
Gerota's  space 

FIG.  82. — Diagram  of  a  Transverse  Section  through  the  Abdomen, 

at  the  level  of  the  Third  Lumbar  Vertebra. 

On  the  left  side,  the  normal  arrangement  of  the  fasciae  is  shown.  On  the 
right  side,  the  course  taken  by  a  peri-nephric  abscess  is  represented.  The  pus 
has  perforated  the  peri-nephric  and  the  lumbo-dorsal  fasciae,  and,  after  passing 
downwards  and  laterally,  has  appeared  at  the  lateral  border  of  the  latissimus 
dorsi  in  the  lumbar  triangle  (of  Petit). 

Abscesses  which  arise  within  the  fascial  envelope  of  the 
abdomen  tend  to  pass  forwards  round  the  abdominal  wall  in  the 
extra-peritoneal  fat. 

The  Quadratus  Lumborum  is  a  flat  muscle  arising  below  from  the  iliac 
crest  and  the  ilio-lumbar  ligament,  which  extends  between  the  crest  and  the 
transverse  process  of  the  fifth  lumbar  vertebra.  It  becomes  narrower  as  it 
passes  upwards  to  be  inserted  into  the  twelfth  rib.  Anteriorly,  it  is  clothed 
by  the  anterior  lamella  of  the  lumbo-dorsal  fascia,  which  separates  it  from 
the  medial  continuation  of  the  fascia  transversalis  (p.  271).  Both  muscles 
acting  together  produce  extension  of  the  vertebral  column  ;  one,  acting  alone, 
produces  lateral  flexion.  The  nerve-supply  is  derived  from  L.  i,  2,  3,  and  4. 

The  Psoas  Major  occupies  the  groove  between  the  bodies  and  transverse 
processes  of  the  lumbar  vertebrae.  It  arises  from  the  twelfth  thoracic  and  all 
the  lumbar  vertebras,  and  passes  downwards  and  laterally  along  the  margin 


THE  ABDOMINAL  WALLS  271 

of  the  brim  of  the  pelvis.  Passing  behind  the  inguinal  ligament,  it  enters 
the  thigh  and  is  inserted  into  the  lesser  trochanter  (p.  406).  This  muscle 
forms  a  fleshy  pad,  which  separates  the  kidney  from  the  vertebral  column. 
It  receives  its  nerve-supply  from  the  anterior  rami  of  L.  2  and  3. 

The  lliacus  fills  up  the  hollow  on  the  ventral  surface  of  the 
ilium  and  has  the  psoas  major  related  to  its  medial  border. 
Most  of  its  fibres  are  inserted  into  the  psoas  tendon.  It  is 
supplied  by  the  femoral  (ant.  crural)  nerve. 

Both  these  muscles  act  together,  and  when  the  lower  limb  is 
free  to  move  they  act  as  flexors  of  the  hip-joint ;  when  the 
lower  limb  is  fixed,  they  act  as  flexors  of  the  trunk. 

The  Fascia  Iliaca,  which  is  continuous  above  with  the  fascia 
trans versalis  and  below  with  the  parietal  layer  of  the  pelvic 
fascia  (p.  356),  covers  both  the  iliacus  and  the  psoas.  It  is  firmly 
attached  to  the  iliac  crest  and  to  the  lateral  part  of  the  inguinal 
ligament.  Opposite  the  femoral  vessels,  it  passes  down  into  the 
thigh,  forming  the  posterior  wall  of  the  femoral  sheath  (p.  402). 

Along  the  line  of  origin  of  the  transversus  from  the  lumbo- 
dorsal  fascia,  the  transversalis  fascia  becomes  adherent  to  or 
partially  blended  with  the  latter.  As  it  is  continued  medially, 
it  is  separated  from  the  quadratus  lumborum  by  the  anterior 
lamella  of  the  lumbo-dorsal  fascia,  but  it  is  in  direct  contact 
with  the  psoas  major  (Fig.  82).  At  the  lateral  border  of  the 
kidney  the  transversalis  fascia  splits  to  enclose  both  the  kidney 
and  the  suprarenal  gland,  but  a  fibrous  partition  separates  the 
two  structures  so  that,  when  the  fascia  is  incised,  the  kidney 
can  be  drawn  out  while  the  suprarenal  gland  remains  in  place. 

The  fascia  which  surrounds  the  kidney  is  termed  the 
peri-nephric  fascia.  It  limits  a  space  (Gerota's),  which  is  closed 
above,  below,  and  to  the  lateral  side,  but  which  is  open  medially, 
where  both  layers  are  continued  across  the  middle  line.  They 
are  separated  from  one  another  by  the  renal  vessels,  the  aorta, 
and  inferior  vena  cava.  The  two  layers  meet  inferiorly  just 
below  the  lower  pole  of  the  kidney,  but  they  may,  abnormally, 
remain  separate  for  a  much  greater  distance.  The  latter  condi- 
tion constitutes  a  predisposing  cause  of  movable  kidney  (p.  353). 

The  abdomen  possesses  a  complete  fascial  envelope,  which  is 
formed  by  (i)  the  fascia  transversalis,  (2)  the  diaphragmatic 
fascia,  (3)  the  peri-nephric  fascia,  (4)  the  fascia  iliaca,  and  (5) 
the  pelvic  fascia.  Prolongations  of  this  fascial  envelope  form 
the  femoral  sheath  and  the  internal  spermatic  or  infundibuliform 
fascia,  which  covers  the  testis  and  the  spermatic  cord. 

The  large  blood-vessels  of  the  abdomen' and  pelvis  lie  inside 


272 


THE  ABDOMEN  AND  PELVIS 


the  fascial  envelope  while  the  great  nerves  lie  external  to  it 

(P-  355)- 

Psoas  Abscess. — A  cold  abscess  resulting  from  tuberculous 
periostitis  or  osteo-myelitis  of  the  lower  thoracic  or  upper 
lumbar  vertebrae  is  limited  in  front  by  the  anterior  longitudinal 
ligament  and  spreads  in  a  lateral  direction.  In  the  lumbar 
region  it  passes  either  into  the  substance  of  the  psoas  major 
or  between  the  muscle  and  its  covering  fascia ;  in  the  thoracic 

Left  infra-colic  compartment 
Supra-colic  compartment 

Left  para-colic  gutter 


Vermiform  process, 
perforated 


Descending  colon 

Psoas  abscess 


FlG.  83. — Diagram  of  a  Transverse  Section  through  the  Abdomen, 

below  the  Lower  Poles  of  the  Kidneys. 

On  the  left  side,  a  psoas  abscess  is  depicted,  spreading  laterally  behind  the 
fascial  envelope  of  the  abdomen.  The  pus  is  separated  from  the  quadrat  us 
lumborum  by  the  anterior  layer  of  the  lumbo- dorsal  fascia,  and  from  the 
descending  colon  by  the  transversalis  fascia. 

On  the  right  side,  an  abscess  is  depicted  in  connection  with  a  retro-caecal, 
extra-peritoneal  vermiform  process.  In  this  case  the  pus  is  situated  inside 
the  fascial  envelope  of  the  abdomen. 

region  it  enters  the  posterior  mediastinum  and,  gravitating 
downwards,  passes  into  the  abdomen  behind  the  medial  lumbo- 
costal  arch  (int.  arcuate  ligament),  which  is  simply  the  thickened 
upper  border  of  the  psoas  fascia.  In  both  instances,  therefore, 
the  abscess  lies  behind  the  psoas  fascia,  and  its  presence  may 
excite  reflex  contraction  of  the  muscle  with  flexion  at  the 
hip-joint.  A  similar  reflex  is  often  observed  in  appendicular 
inflammation,  and  in  other  cases  where  the  muscle  is  irritated. 
Direction  of  Spread. — (i)  The  pus  may  pass  laterally  behind 


THE  ABDOMINAL  WALLS  273 

the  peri-nephric  fascia  and  in  front  of  the  quadratus  lumborum 
(Fig.  83),  and  so  reach  the  anterior  surface  of  the  lumbo-dorsal 
fascia  near  the  origin  of  the  trans  versus  abdominis  (trans  versalis). 
At  this  point  the  peri-nephric  and  trans  versalis  fasciae  become 
continuous,  but  they  are  both  adherent  to  the  origin  of  the 
muscle  and  check  further  spread  in  a  lateral  direction.  The 
pus  may  perforate  the  lumbo-dorsal  fascia  and  enter  the  upper 
lumbar  triangle,  from  which  it  may  spread  to  the  lumbar 
triangle  (of  Petit)  (p.  269). 

(2)  The  pus  may  follow  the  direction  of  the  psoas  major  and 
enter  the  thigh  behind  the  inguinal  ligament.     In  its  course  it 
may  infect  and  erode  the  sacro-iliac  joint,  or  it  may  spread  to  the 
bursa  which  separates  the  tendon  of  the  muscle  from  the  hip-joint. 
When  this  bursa  communicates  with  the  joint,  the  latter  also  may 
become  infected.    This  condition  is  referred  to  again  on  p.  423. 

(3)  The  pus  may  pass  downwards  at  first  and  then,  spreading 
laterally,  gain  the  iliac  fossa  where  it  lies  behind  the  fascia  iliaca. 
Its  presence  in  this  situation  may  be  recognised  on  abdominal 
palpation.    At  the  iliac  crest  both  the  fascia  iliaca  and  fascia 
transversalis  are  bound  down  to  the  bone,  but,  should  the  abscess 
increase  in  size,  their  attachments  are  not  strong  enough  to  limit 
it  to  the  iliac  fossa,  and  it  may  come  towards  .the  surface  near 
the  anterior  superior  iliac  spine.     In  these  cases  it  is  advisable 
to  evacuate  the  pus,  and  the  muscles  may  be  divided  by  a  grid- 
iron incision.    The  transversalis  fascia  is  not  incised,  but  is 
separated  from  the  trans  versus  muscle  until  the  abscess  is  reached. 

(4)  The  pus  may  occasionally  pass  backwards,  following  the 
course  of  the  dorsal  branch  of  a  lumbar  artery.     It  usually 
passes  medial  to  the  sacro-spinalis  and  points  near  the  posterior 
median  line,  or  it  may  spread  upwards  and  downwards  within 
the  sheath  of  the  muscle  (Fig.  83). 

The  Approach  to  the  Kidney  from  behind.— In 
nephropexy  and  other  operations  which  do  not  necessitate  the 
exposure  of  the  ureter,  a  vertical  incision  along  the  lateral  border 
of  the  sacro-spinalis  (erector  spince)  gives  good  access.  After 
the  skin  and  fasciae  have  been  divided,  the  oblique  lower  fibres 
of  the  latissimus  dorsi  are  cut  across  in  the  line  of  the  incision, 
exposing  the  lumbo-dorsal  fascia  (lumbar  aponeurosis),  which 
is  also  incised  vertically.  In  the  upper  part  of  the  wound,  the 
posterior  layer  of  the  peri-nephric  fascia  is  now  exposed,  but, 
below,  the  lateral  margin  of  the  quadratus  lumborum,  which 
crosses  the  wound  obliquely  (p.  270),  must  be  divided  together 

18 


274 


THE  ABDOMEN  AND  PELVIS 


with  the  anterior  layer  of  the  lumbo-dorsal  fascia  on  its  anterior 
surface.  When  the  edges  of  the  wound  are  widely  retracted, 
the  last  thoracic,  ilio-hypogastric  and  ilio-inguinal  nerves  may 
be  seen  running  downwards  and  laterally  behind  the  peri-nephric 


Trapezius 


Latissimus  dorsi 


Spleen  -  - 


Left  kidney  4-  — 


Left  ureter 


I    Lumbo-dorsal  fascia, 
middle  layer 
Quadratus  lumborum 

External  oblique 
4  Sacro-spinalis 


Lumbp-dorsal  fascia, 
posterior  layer 


Glutseus  maximus 


FIG.  84. — The  Position  and  Posterior  Relations  of  the  Kidney. 

On  the  right  side,  the  lower  part  of  the  latissimus  dorsi  has  been  removed 
and  a  rectangular  flap  of  the  posterior  layer  of  the  lumbo-dorsal  fascia  has 
been  turned  laterally.  A  part  of  the  sacro-spinalis  has  been  resected,  exposing 
the  tips  of  the  transverse  processes  of  the  2nd  and  3rd  lumbar  vertebrae  and 
the  middle  layer  of  the  lumbo-dorsal  fascia.  A  rectangular  flap  of  the  fascia 
has  been  turned  laterally  in  order  to  expose  the  quadratus  lumborum. 

On  the  left  side,  the  relations  of  the  spleen  and  left  kidney  to  the  lung  and 
pleural  sac  are  indicated  on  the  surface. 

fascia.    When  the  latter  is  opened,  the  peri-renal  fat  can  readily 
be  separated  from  the  kidney  with  the  finger. 

When  freer  access  is  desired,  e.g.  in  exploratory  operations 
necessitating  the  exposure  of  the  ureter,  the  oblique  lumbo-ilio- 
inguinal  incision  may  be  preferred.  It  commences  above  in 
the  angle  between  the  twelfth  rib  and  the.  sacro-spinalis,  and  is 
carried  downwards  and  laterally  in  the  direction  of  the  anterior 
superior  iliac  spine.  If  necessary,  it  may  be  continued  medially 


THE  ABDOMINAL  WALLS  275 

above  the  lateral  part  of  the  inguinal  ligament,  being  limited 
by  the  abdominal  inguinal  (int.  abd.)  ring. 

The  lower  fibres  of  the  latissimus  dorsi  are  cut  across,  exposing 
the  lumbo-dorsal  fascia  above  and  the  internal  oblique  below. 
These  structures  are  divided  in  the  line  of  the  skin  incision,  and 
the  lateral  part  of  the  wound  is  deepened  through  the  transversus 
abdominis  until  the  fascia  trans versalis  is  reached.  The  pos- 
terior layer  of  the  peri-nephric  fascia,  which  is  the  continuation 
of  the  fascia  transversalis  in  a  medial  direction,  has  already  been 
exposed  by  the  division  of  the  lumbo-dorsal  fascia.  It  is  now 
incised,  and  the  kidney  and  the  commencement  of  the  ureter 
are  found  in  the  peri-renal  fat.  As  the  ureter  is  traced  down- 
wards, it  becomes  necessary  to  divide  the  fascia  transversalis, 
which  has  so  far  been  preserved  intact.  This  is  done  with  great 
care  because,  owing  to  the  scantiness  of  the  extra-peritoneal 
fat  in  this  region,  there  is  danger  of  opening  the  peritoneal 
cavity.  In  addition,  the  descending  colon  is  retro-peritoneal 
and  the  posterior  wall  of  the  gut  or  its  blood-vessels  may  be 
injured  unless  great  care  is  exercised. 

When  the  whole  incision  is  employed,  the  ureter  can  be 
traced  from  its  commencement  in  Gerota's  space  through  the 
anterior  layer  of  the  peri-nephric  fascia  into  the  extra-peritoneal 
fat,  and  then  downwards  to  the  pelvis. 

In  the  process,  the  peritoneum  is  stripped  off  the  posterior 
abdominal  wall  and  serves  to  keep  the  abdominal  contents 
away  from  the  field  of  the  operation. 

The  danger  of  opening  the  pleural  sac  at  the  upper  end  of 
the  wound  must  also  be  borne  in  mind.  The  lower  limit  of  the 
sac  posteriorly  (p.  509)  lies  in  front  of  the  last  rib,  at  the  point 
where  the  rib  is  crossed  by  the  lateral  margin  of  the  sacro-spinalis. 
Frequently  the  last  rib  is  so  short  that  its  extremity  cannot  be 
felt.  In  these  cases  the  eleventh  rib  may  be  mistaken  for  the 
twelfth,  and  if  so,  the  pleura  will  be  opened  at  the  upper  part 
of  the  wound  as  the  incision  is  deepened.  This  danger  can  be 
avoided  by  counting  the  ribs  from  above  downwards  and  so 
determining  whether  the  lowest  palpable  rib  is  the  eleventh  or 
the  twelfth.  Further,  on  rare  occasions,  the  pleura  may  lie  at 
a  lower  level  than  normal,  and  cross  the  apex  of  the  angle  between 
the  twelfth  rib  and  the  sacro-spinalis.  It  is  then  very  difficult 
to  avoid  opening  the  pleural  sac. 

It  may  be  necessary,  e.g.  after  radiographic  localisation  of 
ureteral  calculi,  to  expose  the  ureter  without  exploring  the  kidney, 


276  THE  ABDOMEN  AND  PELVIS 

and,  in  this  case,  the  oblique  incision  need  not  extend  so  high 
as  the  angle  between  the  sacro-spinalis  and  the  last  rib.  The 
fascia  transversalis  may  be  incised  as  soon  as  it  is  reached,  and 
the  surgeon  then  works  medially,  stripping  the  peritoneum  off 
the  posterior  abdominal  wall,  until  the  anterior  surface  of  the 
psoas  major  is  recognised.  On  the  other  hand,  the  fascia 
transversalis  may  be  left  intact  and  the  surgeon  works  medially, 
stripping  it  and  the  fascia  iliaca  forwards  as  a  continuous  sheet. 
When  the  psoas  major  is  reached,  the  fascia  is  carefully  torn 
through  with  the  finger  nail.  Whatever  method  is  employed 
the  ureter  will  be  found  adherent  to  the  posterior  aspect  of  the 
peritoneum,  and  its  presence  there  can  readily  be  detected  if  the 
pulp  of  the  finger  is  turned  forwards  and  lightly  drawn  across 
its  course.  When  it  has  been  separated  from  the  peritoneum, 
the  ureter  can  be  brought  up  to  the  surface  and  incised  to  permit 
of  exploration  with  probes  or  the  removal  of  a  calculus.  Owing 
to  its  rich  blood-supply  (p.  354),  incisions  in  the  ureter  soon  heal, 
and,  for  the  same  reason,  complete  isolation  of  the  duct  is  not 
followed  by  damage  from  sloughing. 


THE   ABDOMINAL   CAVITY. 

The  differences  which  exist  between  the  living  subject  and 
the  dissecting-room  cadaver  are  probably  more  marked  in  the 
abdomen  than  in  any  other  part  of  the  body.  The  action  of 
the  preservatives  used  not  only  renders  firm  those  organs  which 
are  pliant  in  life,  such  as  the  liver  and  the  spleen,  but  also 
produces  shrinkage  of  the  abdominal  contents  and  retraction 
of  the  anterior  wall.  In  addition  the  living  peritoneum  possesses 
a  certain  amount  of  mobility  on  the  extra-peritoneal  fat,  and 
can  stretch  or  be  stretched  without  tearing,  but  both  these 
characteristic  features  disappear  after  death.  As  a  result,  the 
positions  of  viscera  relative  to  the  vertebral  column,  as  found 
in  the  cadaver  preserved  and  dissected  in  the  horizontal  position, 
differ  somewhat  from  those  which  they  occupy  in  the  living 
subject,  more  especially  when  the  body  is  in  the  erect  posture. 

With  the  exception  of  the  retroperitoneal  viscera,  which  are 
practically  fixed,  the  positions  of  viscera  relative  to  the  surface 
vary  within  wide  limits.  The  influences  which  govern  these  varia- 
tions are  (i)  posture,  (2)  the  personal  factor,  (3)  the  physiological, 
and  (4)  the  pathological  condition  at  the  time  of  examination. 


THE  ABDOMINAL  CAVITY  277 

The  Peritoneum  is  a  highly  absorptive  serous  membrane, 
which  lines  the  abdominal  and  pelvic  cavities  (parietal  layer), 
and  is  more  or  less  intimately  related  to  the  viscera  contained 
by  them  (visceral  layer).  In  the  male  it'  forms  a  completely 
closed  sac,  but  in  the  female  it  communicates  with  the  cavities 
of  the  uterus  and  vagina  through  the  ostium  abdominale  of  the 
uterine  (Fallopian)  tube.  Infective  conditions,  therefore,  may 
ascend  to  the  peritoneal  sac  through  the  vagina,  uterus,  and 
tubes,  as,  for  example,  in  acute  gonorrhceal  peritonitis. 

The  deep  surface  of  the  anterior  abdominal  wall  is  completely 
lined  by  peritoneum.  Below  the  umbilicus  it  forms  an 
uninterrupted  sheet  so  that  when  the  cavity  has  been  opened, 
the  hand  may  be  introduced  and  passed  across  to  the  opposite 
s:de  without  meeting  any  normal  obstruction.  Above  the 
umbilicus,  a  fold  of  peritoneum,  consisting  of  two  layers — the 
falciform  ligament — passes  backwards  to  the  liver  and  forms 
an  imperfect  partition.  Its  lower  border,  where  the  two 
constituent  layers  become  continuous,  is  free  and  contains  the 
ligamentum  teres  and  the  associated  para-umbilical  veins  (p.  243). 
Although  its  anterior  attachment  is  in  the  middle  line,  the 
falciform  ligament  passes  backwards  and  slightly  to  the  right. 
On  this  account,  when  supra-umbilical  median  incisions  are 
enlarged  in  a  downward  direction,  they  should  be  carried  round 
the  left  s'de  of  the  umbilicus,  so  as  to  obviate  the  necessity  for 
cutting  through  the  ligamentum  teres  and  the  associated  veins. 

The  peritoneum  lining  the  anterior  abdominal  wall  sweeps 
upwards  on  to  the  inferior  surface  of  the  diaphragm,  and  is 
then  reflected  on  to  the  liver  (Fig.  85)  and  stomach.  Between 
the  hepatic  and  gastric  reflections,  the  peritoneum  on  the  under 
surface  of  the  diaphragm  becomes  continuous  with  the  anterior 
layer  of  the  lesser  omentum. 

In  Fig.  85  the  peritoneum  is  shown  passing  from  the 
diaphragm  to  the  liver  in  two  layers,  which  cover  its  anterior 
and  posterior  surfaces  and  meet  on  the  inferior  surface  at  the 
porta  hepatis  (transverse  fissure).  They  then  descend  to  the 
lesser  curvature  of  the  stomach  as  a  broad  sheet  which  is  termed 
the  lesser  omentum.  After  enclosing  the  stomach  and  con- 
stituting its  serous  coat  they  again  meet  one  another,  and 
descend  for  a  variable  distance  towards  the  pelvis.  Inferiorly 
they  are  folded  sharply  upwards  and  ascend  to  the  transverse 
colon.  This  large  peritoneal  sheet,  which  connects  the  transverse 
colon  to  the  stomach,  is  termed  the  greater  omentum. 

18  a 


278 


THE  ABDOMEN  AND  PELVIS 


Originally  it  consisted  of  two  layers  above  and  four  layers  below, 
as  shown  in  Fig.  85,  but  these  layers  may  become  completely 
fused,  and  in  the  living  subject  it  is  not  always  possible  to 
distinguish  more  than  one  layer. 


Lesser  omentum 


Stomach 


Omental  bursa 
(O.T.  small  sac) 

Great  sac 


Greater  omentum 


Uterus 
Urinary  Bladder 


Liver 


Epiploic  foramen 
(O.T.  foramen 
of  Winslow) 


Pancreas 

Duodenum, 
3rd  part 
Transverse  colon 


Mesentery  of 
small  intestine 

Small  intestine 


Rectum 


FIG.  85. — Sagittal  Section  of  Abdomen  showing  the  arrangement 
of  the  Peritoneum. 

The  two  posterior  layers  of  the  greater  omentum,  having 
enclosed  the  transverse  colon,  pass  backwards  and  upwards  to 
the  posterior  abdominal  wall,  as  the  transverse  meso-colon, 
and  there  they  separate  along  the  anterior  bordei  of  the  pancreas 
on  a  level  with  the  second  lumbar  vertebra.  The  superior  layer 
passes  upwards  over  the  posterior  abdominal  wall  and  is  then 


THE  ABDOMINAL  CAVITY  279 

reflected  forwards  on  to  the  liver.  The  inferior  layer  passes 
downwards  and  forms  a  complete  covering  to  the  posterior 
abdominal  wall  below  the  pancreas.  Along  a  line  passing 
obliquely  downwards  and  to  the  right,  it  'is  lifted  off  the  wall 
to  form  the  mesentery,  which  encloses  the  jejunum  and  ileum. 
After  covering  the  pelvic  viscera  (p.  357),  this  layer  passes 
upwards  on  the  anterior  abdominal  wall. 

It  will  be  seen  from  Fig.  85  that  a  portion  of  the  peritoneal 
cavity  is  shut  off  behind  the  stomach.  This  is  the  Omental 
Bursa  (Lesser  Sac).  It  is  a  developmental  diverticulum 
(p.  303)  of  the  great  sac,  with  which  it  communicates  through 
a  single  opening,  the  epiploic  foramen  (of  Winslow). 

The  Greater  Omentum  forms  a  protective  covering  over 
the  abdominal  viscera  below  the  level  of  the  stomach.  It 
contains  a  variable  amount  of  fat,  and  is  usually  the  first  structure 
seen  when  the  abdomen  is  opened.  The  lower  and  the  lateral 
margins  are  free,  and  it  can  therefore  be  easily  moved  about 
in  abdominal  operations.  In  addition,  the  greater  omentum 
wanders  to  any  region  of  the  abdomen  where  inflammatory  pro- 
cesses exist,  and  the  surrounding  adhesions  which  it  forms  are  of 
great  value  in  limiting  the  spread  of  infection.  On  this  account 
it  has  been  termed  by  Morison  the  "policeman  of  the  abdomen." 

The  Lesser  Omentum  passes  from  the  lesser  curvature  of 
the  stomach  and  the  corresponding  border  of  the  first  inch  and 
a  half  of  the  duodenum  to  the  porta  (transverse  fissure)  of  the 
liver.  The  two  layers  of  which  it  consists  are  closely  applied 
to  one  another,  and  form  a  thin,  transparent  sheet,  save  near 
the  right  border  where  they  are  separated  by  the  portal  vein, 
bile-duct,  and  hepatic  artery.  Round  this  border,  which  is 
free  and  unattached,  the  two  layers  become  continuous  (Fig.  86). 
Occasionally  the  lesser  omentum  is  continued  beyond  the  vessels 
and  duct,  and  receives  attachment  to  the  inferior  surface  of  the 
gall-bladder.  Its  free  border  may  then  be  traced  downwards 
over  the  duodenum  to  the  transverse  colon,  and  on  this  account 
the  additional  part  is  called  the  hepato-colic  ligament.  It 
contains  no  vessels  of  any  size,  but  the  gall-bladder  lies  within 
its  upper  attachment.  It  may  be  cut  through  parallel  to  the 
gall  bladder  in  exploring  the  epiploic  foramen. 

The  Epiploic  Foramen  (of  Winslow)  lies  behind  the  right 
free  border  of  the  lesser  omentum.  It  is  bounded  above  by  the 
liver  (caudate  lobe),  and  behind  by  the  peritoneum  which  covers 
the  inferior  vena  cava.  Below  it  is  limited  by  the  first  part  of 

18  b 


280 


THE  ABDOMEN  AND  PELVIS 


the  duodenum.  In  certain  cases,  e.g.  examination  of  the  bile- 
duct,  it  is  necessary  to  explore  the  epiploic  foramen.  This  can 
be  effected  by  passing  the  finger  backwards  and  to  the  left  along 
the  postero-lateral  surface  of  the  gall  bladder  till  it  reaches 
the  neck.  The  finger  then  slips  behind  the  right  margin  of  the 
lesser  omentum  and  enters  the  foramen. 


9  10  II  12 

FIG.  86. — Transverse  Section  of  Abdomen  at  the"  level  of  the 
Epiploic  Foramen  (of  Winslow). 


1.  Omental  bursa  (O.T.  small  sac). 

2.  Omental  tubercle  of  liver. 

3.  Great  sac. 

4.  Stomach. 

5.  Gastro  -  splenic      ligament 

gastro-splenic  omentum). 

6.  Spleen. 

7.  Lieno-renal  ligament. 

8.  Left  kidney. 

9.  Diaphragm. 


(O.T. 


10.  Aorta. 

11.  Inferior  vena  cava. 

12.  Right  kidney.  [Winslow). 

13.  Epiploic  foramen  (O.T.  foramen  of 

14.  Liver. 

15.  Gallbladder. 

16.  Bile-duct. 

17.  Portal  vein. 

1  8.  Hepatic  artery. 
19.   Falciform  ligament. 


The  Omental  Bursa  (Lesser  Sac)  extends  upwards  between 
the  liver  and  the  diaphragm  to  the  upper  end  of  the  caudate 
(Spigelian)  lobe  (Fig.  85).  Below  it  rarely  extends  beyond  the 
transverse  colon,  owing  to  the  fusion  of  the  anterior  and  posterior 
layers  of  the  greater  omentum.  Its  anterior  wall  is  formed, 
from  above  downwards,  by  (i)  the  liver,  (2)  the  lesser  omentum, 
(3)  the  postero-inferior  surface  of  the  stomach,  and  (4)  the  two 
anterior  layers  of  the  greater  omentum.  Its  posterior  wall  is 
formed,  from  below  upwards,  by  (i)  the  transverse  colon,  (2) 


THE  ABDOMINAL  CAVJTY 


281 


the  transverse  meso-colon,  (3)  the  anterior  surface  of  the  pancreas, 
and  (4)  the  upper  pole  of  the  left  kidney,  the  left  suprarenal 
gland,  and  the  diaphragm. 

When  a  transverse  section  is  made  through  the  abdomen 
so  as  to  pass  through  the  epiploic  foramen,  the  connection  of 
the  omental  bursa  with  the  great  sac  is  at  once  demonstrated 
(Fig.  86).  On  the  left  side,  at  this  level,  the  two  layers  of 


FIG.  87. — Transverse  Section  of  Abdomen,  immediately  below  the 
Epiploic  Foramen. 


12.  Inferior  vena  cava. 

13.  Right  suprarenal  gland. 

14.  Right  kidney. 

15.  Great  sac. 

16.  Bile-duct. 

17.  Gastro-duodenal  artery. 

1 8.  Liver. 

19.  Duodenum,  ist  part. 


ii.  Portal  vein.  20.  Falciform  ligament. 


1.  Omental  bursa  (O.T.  small  sac). 

2.  Stomach.    3.  Great  sac.    4.  Great  sac. 

5.  Gastro-splenic  ligament  (O.T.  gastro- 

splenic  omentum). 

6.  Lieno-renal  ligament. 

7.  Left  kidney. 

8.  Pancreas. 

9.  Left  suprarenal  gland. 
10.  Aorta. 

peritoneum  which  enclose  the  stomach  pass  backwards  from  the 
fundus  to  form  the  gastro- splenic  ligament.  At  the  hilum  of  the 
spleen,  the  lateral  (originally  anterior)  layer  gives  a  complete 
investment  to  that  organ,  which  therefore  projects  into  the 
supra-colic  compartment  of  the  peritoneal  cavity.  From  the 
hilum,  the  two  layers  pass  backwards  to  the  left  kidney  as  the 
lieno-renal  ligament  and  then  they  diverge,  the  one  lining  the 
great  sac  and  the  other  the  omental  bursa.  These  two  folds, 
together  with  the  hilum  of  the  spleen,  form  the  left  boundary 


282  THE  ABDOMEN  AND  PELVIS 

of  the  omental  bursa  and  completely  shut  it  off  from  the  great 
sac  on  this  side.  Below  the  level  of  the  spleen,  the  gastro- 
splenic  ligament  is  directly  continuous  with  the  two  anterior 
layers  of  the  greater  omentum,  i.e.  there  is  no  break  in  the 
continuity  of  the  wall  of  the  bursa. 

Transverse  sections  made  through  the  omental  bursa  below 
the  epiploic  foramen  show  it  as  a  completely  closed  sac.  In 
Fig.  87  the  section  passes  through  the  pylorus  and  the  first 
part  of  the  duodenum.  The  peritoneum  on  the  posterior  aspect 
of  the  stomach  passes  to  the  right  and  covers  rather  less  than 
the  first  inch  of  the  duodenum  before  it  passes  backwards  on  to 
the  head  of  the  pancreas. 

This  reflection  forms  the  right  border  of  the  omental  bursa, 
and  the  hepatic  artery  passes  forwards  round  it  in  order  to 
reach  the  lesser  omentum. 

Drainage  of  the  Peritoneal  Cavity.— Collections  of  fluid 

in  the  peritoneal  cavity  differ  in  situation  according  to  the  position 
of  the  patient,  and,  unless  they  are  limited  by  adhesions,  they 
spread  in  a  downward  direction  when  the  patient  is  in  the  erect 
or  semi-sitting  posture.  In  the  supine  position,  they  will  tend 
to  pass  upwards  towards  the  diaphragm.  In  the  post-operative 
treatment  of  inflammatory  effusions,  the  patient  is  usually  placed 
in  the  Fowler  (semi-sitting)  position  in  order  to  diminish  the 
risk  of  upward  spread  into  the  sub-diaphragmatic  region  (p.  283). 

The  peritoneal  cavity  is  naturally  subdivided  into  the  pelvis 
and  the  abdomen  proper,  and  the  latter  is  further  subdivided 
by  the  large  sheets  of  peritoneum  which  form  the  greater 
omentum  and  the  mesentery. 

The  uppermost  or  Supra  -  colic  Compartment  lies  above 
and  in  front  of  the  greater  omentum.  It  is  partially  subdivided 
into  a  right  and  a  left  half  by  the  falciform  ligament  of  the  liver, 
and  its  contents  include  the  liver,  the  gall-bladder,  the  stomach, 
the  first  part  of  the  duodenum,  the  spleen,  and  the  upper  poles 
of  both  kidneys.  The  omental  bursa  (lesser  sac)  may  be  regarded 
as  a  large  diverticulum  of  the  supra-colic  compartment.  In 
addition  other,  smaller,  recesses  occur :  (i)  between  the  upper 
surface  of  the  liver  and  the  under  surface  of  the  diaphragm 
(Fig.  85) ;  (2)  the  hepato-renal  recess  of  Morrison,  between 
the  under  surface  of  the  liver  above  and  the  right  kidney  and  the 
right  (hepatic)  flexure  of  the  colon  below ;  and  (3)  between  the 
spleen  and  the  left  kidney. 

Anteriorly,  the  supra-colic  compartment  is  bounded  by  the 


THE  ABDOMINAL  CAVITY  283 

anterior  abdominal  wall ;  posteriorly,  it  is  limited  by  the  lesser 
omentum,  stomach,  and  greater  omentum,  which  together  form 
an  oblique  surface,  sloping  backwards  and  to  the  right.  When 
pus  or  septic  fluid,  e.g.  from  a  leaking  ulcer  of  the  duodenum  or 
anterior  wall  of  stomach,  is  present  in  this  compartment,  it  may 
remain  localised  owing  to  adhesions  between  the  greater  omentum 
and  the  anterior  abdominal  wall.  Its  downward  spread  is  thus 
prevented,  and  owing  to  the  slope  of  the  posterior  wall,  the  fluid 
tends  to  pass  into  the  hepato-renal  recess.  With  the  body  in 
the  horizontal  position  it  readily  spreads  from  this  situation 
round  the  free  border  of  the  right  triangular  (lateral)  ligament 
of  the  liver  into  the  recess  between  the  liver  and  the  diaphragm. 
The  infection  of  this  intra-peritoneal  subphrenic  area  is  a  very 
serious  condition,  because  the  lymphatics  of  the  peritoneum  on 
the  under  surface  of  the  diaphragm  communicate  very  freely 
with  those  of  the  pleura,  and  empysema  or  abscess  of  the  lung 
may  complicate  the  existing  peritonitis,  with  fatal  results. 

The  hepato-renal  recess  of  Morison  may  be  drained  through 
an  incision  made  below  the  twelfth  rib  and  at  the  lateral  margin 
of  the  kidney.  This  pierces,  in  turn,  the  skin,  fasciae,  latissimus 
dorsi,  the  obliques,  transversus,  transversalis  fascia,  and 
peritoneum.  A  tube  thus  passed  into  the  recess  affords  good 
drainage  if  the  patient  is  placed  in  the  Fowler  (semi-sitting) 
attitude.  In  this  way  the  spread  of  infection  into  the  subphrenic 
danger  zone  may  be  successfully  prevented. 

After  perforation  of  an  ulcer  on  the  posterior  wall  of  the 
stomach,  the  fluid  may  be  prevented  from  escaping  from  the 
omental  bursa  by  adhesions  closing  the  epiploic  foramen  (of 
Winslow).  The  bursa  then  becomes  distended  and  may  best 
be  drained  by  means  of  a  tube  passed  through  the  lesser  omentum 
from  the  median  incision,  which  is  employed  in  such  cases  (p.  294). 
In  addition  a  counter  opening  may  be  made  in  the  left  side, 
below  the  twelfth  rib  and  lateral  to  the  descending  colon,  and  a 
tube  passed  upwards  and  medially  in  front  of  the  left  colic 
flexure  may  be  introduced  into  the  bursa  through  the  lower 
part  of  the  gastro-splenic  ligament. 

If  the  epiploic  foramen  is  patent,  the  fluid  passes  out  into 
the  supra-colic  compartment  and  at  once  invades  the  hepato- 
renal  recess  of  Morison  (Fig.  86).  In  this  case,  both  the  recess 
and  the  bursa  will  require  to  be  drained. 

The  Infra -colic  Compartment  lies  behind  the  greater 
omentum,  transverse  colon,  and  meso-colon,  and  is  subdivided 


284 


THE  ABDOMEN  AND  PELVIS 


into  two,  a  right  and  a  left,  by  the  mesentery,  which  extends 
from  the  left  side  of  the  second  lumbar  vertebra  downwards 


FIG.  88. — The  Posterior  Wall  of  the  Infra-colic  Compartment.  The  greater 
omentum  and  the  transverse  colon  have  been  thrown  upwards.  The 
mesentery  has  been  divided  close  to  its  root  and  removed  together  with 
the  coils  of  the  jejunum  and  ileum.  A  small  part  of  the  pelvic  colon 
and  its  mesentery  has  been  resected  to  expose  the  pelvic  portion  of  the 
left  ureter. 

and  to  the  right  for  about  six  inches  and  terminates  at  the 
ileo-colic  junction.  Coils  of  small  intestine  occupy  both  sub- 
divisions, and  must  be  displaced  when  the  compartment  is  being 
explored.  This  displacement,,  to  be  effectual,  must  be  at  right 


THE  ABDOMINAL  CAVITY  285 

angles  to  the  line  of  mesenteric  attachment,  i.e.  upwards  and  to 
the  right  or  downwards  and  to  the  left.  Owing  to  the  "  lie  "  of 
the  mesentery;  endeavours  to  draw  the  gut  downwards  and  to  the 
right  or  upwards  and  to  the  left  cannot  meet  with  much  success. 

The  right  infra- colic  compartment,  bounded  above  by  the 
root  of  the  transverse  meso-colon,  to  the  right  by  the  ascending 
colon,  and  to  the  left  by  the  root  of  the  mesentery,  is  roughly 
triangular  in  shape  (Fig.  88).  It  can  be  exposed  by  drawing 
the  greater  omentum  upwards  and  displacing  the  coils  of  small 
intestine  downwards  and  to  the  left.  The  peritoneum  on  its 
posterior  wall  covers  the  lower  pole  of  the  right  kidney,  the 
second  and  third  parts  of  the  duodenum,  a  small  part  of  the 
head  and  neck  of  the  pancreas,  and  the  right  ureter  and  psoas 
major  muscle  (Fig.  88). 

Owing  to  the  protection  which  it  receives  from  the  greater 
omentum,  this  compartment  is  rarely  infected  by  a  downward 
spread,  and  as  its  lower  extremity  is  closed  (Fig.  88),  it  is  not  com- 
monly infected  by  an  upward  spread  from  the  pelvis.  Primary 
infection  is  rare ;  it  is  usually  due  to  the  vermiform  process 
(P-  331)-  Drainage  may  be  obtained  through  the  appendicular 
wound  by  means  of  a  tube  passed  upwards  and  to  the  left, 
medial  to  the  ascending  colon  and  behind  the  greater  omentum. 

The  left  infra-colic  compartment  is  bounded  to  the  right  by 
the  root  of  the  mesentery  and  to  the  left  by  the  descending  and 
iliac  cola  ;  below,  it  is  bounded  on  the  left  side  by  the  ascending 
part  of  the  pelvic  meso-colon,  but  on  the  right  side  it  opens 
freely  into  the  pelvis  (Fig.  88).  It  can  be  exposed  by  drawing 
the  greater  omentum  upwards  and  displacing  the  small  intestine 
upwards  and  to  the  right.  The  peritoneum  on  its  posterior  wall 
covers  the  lower  pole  of  the  left  kidney,  the  inferior  surface  of 
the  body  of  the  pancreas,  and  the  duodeno-jejunal  flexure 
above ;  the  left  ureter,  the  inferior  mesenteric  and  superior 
hsemorrhoidal  vessels,  and  the  left  psoas  major  below. 

Either  infra-colic  compartment  may  be  the  site  of  a 
tuberculous  abscess,  following  the  breaking  down  of  caseous 
mesenteric  lymph  glands. 

The  right  para-colic  gutter  lies  along  the  lateral  side  of 
the  ascending  colon,  and  its  floor  is  formed  by  the  peritoneal 
reflection  from  the  gut  to  the  lateral  wall  of  the  abdomen.  Above, 
it  opens  into  the  hepato -renal  recess  of  Morison ;  below,  it 
passes  round  or  behind  the  caecum  and  communicates  with  the 
pelvis  over  the  medial  border  of  the  psoas  major.  Infection  of 


286  THE  ABDOMEN  AND  PELVIS 

this  gutter  may  occur  by  downward  spread  from  Morison's 
pouch  and  the  omental  bursa,  and  this  condition  may  be  suspected 
in  those  cases  of  perforated  gastric  or  duodenal  ulcer  in  which 
pain  is  felt  over  the  right  iliac  fossa.  Owing  to  the  presence 
of  this  channel,  stomach  contents  may  be  found  in  the  pelvis,, 
even  when  the  greater  omentum  is  adherent  to  the  anterior 
abdominal  wall.  Pus  from  a  retro-csecal  (intra-peritoneal, 
p.  333)  abscess  may  spread  upwards  along  the  right  para-colic 
gutter  into  the  loin  and  possibly  to  the  subphrenic  danger  zone. 

Drainage  is  conveniently  carried  out  through  a  stab  wound 
just  above  the  iliac  crest  by  means  of  a  tube,  which  can  be 
drawn  out  in  front  through  the  appendicular  incision.  The 
wound  must  be  on  the  lateral  side  of  the  ascending  colon,  and 
great  care  must  be  taken  to  avoid  injuring  the  gut. 

The  left  para-colic  gutter  extends  along  the  lateral  side 
of  the  descending  and  iliac  cola  and  opens  freely  into  the  pelvis 
at  its  lower  end.  Its  upper  extremity  is  separated  from  the 
spleen  and  the  lieno-renal  recess  by  the  phrenico-colic  ligament, 
a  fold  of  peritoneum  which  passes  laterally  from  the  left  colic 
(splenic)  flexure  to  the  diaphragm.  It  may  be  infected  from 
the  supra-colic  compartment  or  by  upward  spread  from  the 
pelvis.  Drainage  may  be  obtained  through  a  small  grid-iron 
incision  in  the  left  iliac  fossa,  and  a  stab  wound  similar  to  that 
employed  on  the  right  side.  A  tube  may  then  be  passed  through 
from  back  to  front. 

The  basin  of  the  Pelvis  is  formed  by  the  utero-rectal  pouch 
in  the  female  and  by  the  recto-vesical  pouch  in  the  male. 
Primary  infection  is  due  to  pathological  conditions  of  the 
vermiform  process  (p.  331)  or  the  pelvic  viscera.  Secondary 
infection  is  extremely  common,  as  both  para-colic  gutters,  the 
supra-colic  compartment  (in  the  absence  of  omental  adhesions), 
and  both  infra-colic  compartments  drain  into  the  pelvis. 

In  the  female,  owing  to  the  peritoneal  relations  of  the  vagina 
(p.  387),  the  pelvis  may  be  drained  through  an  incision  in  the 
upper  part  of  the  posterior  fornix.  It  has  been  suggested  that, 
in  the  male,  drainage  may  be  obtained  through  an  incision  into 
the  rectum  from  the  bottom  of  the  recto-vesical  pouch.  The 
usual  method,  however,  is  to  drain  by  means  of  tubes  passed 
downwards  and  backwards  from  a  median  supra-pubic  incision, 
or  downwards  and  medially  from  iliac  grid-iron  incisions. 

In  all  cases  of  pelvic  inflammation,  the  patient  is  placed  in 
the  Fowler  (semi-sitting)  posture,  and  the  assistance  of  gravity 


THE  ABDOMINAL  CAVITY 


287 


is  obtained  to  prevent  the  upward  spread  into  the  various 
compartments  of  the  abdomen  proper. 

Congenital  Hernise. — In  a  three  weeks'  human  embryo, 
the  alimentary  canal  may  be  subdivided  into  the  fore-gut,  the 
mid-gut,  and  the  hind-gut  (Fig.  89).  They  form  a  tube,  which 
is  closed  at  its  cephalic  and  caudal  ends,  but  which  communicates 
with  the  yolk-sac  through  the  vitello-intestinal  duct.  At  the 
junction  of  the  mid-  and  the  hind-gut,  the  allantois  forms  a 
short  blind  diverticulum  which  grows  into  the  body-stalk.  At 
this  period  the  mesoderm  lining  the  ccelom,  or  body-cavity,  of 
the  embryo  is  directly  continuous  with  the  mesoderm  lining 


Spinal  part  of  neural  tube 

Notochord 
Fore 
Hind-brain 


Mid-gut 

|  Amnion  cavity 

Ectoderm  of  amnion 

Mesoderm  of  amnion 

Hind-gut 


Mid-brain  „ 


Fore-brain 
Stomatodaeum 

Pericardium  (heart  not  shown) 

Rudiment  of  liver 


Allantcic  diverticulum 
Mesoderm  of  yolk-sac 


Umbilical  orifice    Entoderm 
FIG.  89. — Schema  of  Sagittal  Section  of  Embryo,  after  the  formation 
of  the  Head  and  Tail  Folds. 

the  cavity — exo-ccelom — in  which  the  yolk-sac  lies,  and  con- 
sequently the  two  spaces  communicate  with  one  another.  The 
anterior  or  cephalic  part  of  the  ccelom  is  destined  to  form  the 
pleural  and  pericardial  sacs,  while  the  rest  becomes  the  peritoneal 
cavity.  As  the  amnion  (Fig.  89),  which  at  first  lies  dorsal  to 
the  embryo,  grows  round  its  ends  and  sides,  the  exo-ccelom  is 
encroached  on,  and  the  body-stalk  is  brought  closer  to  the 
yolk-sac.  In  this  way  the  umbilical  cord  is  formed,  and  at  first 
it  contains  the  yolk-sac,  the  rapidly  narrowing  vitello-intestinal 
duct,  and  the  remains  of  the  exo-ccelom  in  addition  to  the 
blood-vessels  of  the  body-stalk,  the  whole  being  surrounded  by 
the  amnion  (Fig.  90). 

As  the  abdominal  part  of  the  alimentary  canal  increases  in 
length,  it  drags  the  peritoneum  away  from  the  dorsal  wall,  and 


288 


THE  ABDOMEN  AND  PELVIS 


so  acquires  a  dorsal  mesentery.  A  loop  of  gut  is  thus  formed, 
and  as  the  abdominal  walls  do  not  grow  at  the  same  rapid  rate, 
it  descends  through  the  large  patent  umbilicus  and  lies  in  the 
exo-ccelom  within  the  umbilical  cord.  At  the  end  of  the  third 
month  the  abdominal  cavity  is  large  enough  to  contain  all  its 
viscera,  and  the  intestinal  loop  returns  into  the  abdomen.  The 
exo-ccelom  then  becomes  completely  obliterated,  and  no  trace 


CEsophagus 


Rudiment  of  respiratory  system 
Notochord  j 

Medulla  spinalis 


Ectoderm  of  embryo 


Liver  diverticulum  branching  in  septum  transversum 
j  Stomach 

Dorsal  pancreas  rudiment 

Ventral  pancreas  rudiment 
Peritoneal  part  of  ccelum 
Caecum 

Peritoneal  part  of 
celum 

Wolffian  duct 


Rectum 


Hypophysis-    


Cloacal  membrane 


Rathke's  pouch 

Ectoderm  of  amnion 

Mesoderm  of  amnion 

Cerebral  hemisphere 


Umbilical  cord 
Placental  mesoderm 


Pericardium         | 
Gall-bladder  rudiment 


'I  Yolk-sac 

Septum  transversum 


FIG.  90. — Schema  of  a  Sagittal  Section  through  a  Human  Embryo, 
after  the  rotation  of  the  intestinal  loop. 

of  it  should  be  found  in  the  umbilical  cord  at  birth.  Thus 
during  the  second  and  third  months  the  human  embryo  normally 
possesses  an  umbilical  hernia.  If  the  loop  of  gut  fails  to  return 
within  the  abdomen,  or  if  the  exo-ccelom  remains  patent  and 
retains  its  connection  with  the  peritoneal  cavity,  a  congenital 
umbilical  hernia  will  result. 

Congenital  diaphragmatic  hernia  is  due  to  imperfect  develop- 
ment of  the  septum  transversum,  which  ought  to  separate 
the  pleural  and  peritoneal  sacs  completely  from  one  another. 


THE  ABDOMINAL  CAVITY  289 

The  site  of  the  hernia  lies  postero-lateral  to  the  oesophageal 
opening  in  the  diaphragm,  as  this  is  normally  the  last  part  of 
the  diaphragm  to  develop. 

Congenital  inguinal  hernia  is  dealt  with  on  p.  259. 

The  Stomach  is  almost  completely  invested  by  peritoneum, 
and  consequently  possesses  a  wide  range  of  movement.  Its 
proximal  or  cardiac  end,  however,  is  firmly  fixed  in  position 
owing  to  its  continuity  with  the  oesophagus.  It  lies  behind  the 
seventh  left  costal  cartilage  one  inch  from  the  median  plane, 
and  at  a  depth  of  four  inches  from  the  anterior  surface  of  the 
body.  On  the  posterior  surface  the  cardia  can  be  mapped  out 
at  a  distance  of  one  inch  to  the  left  of  the  ninth  thoracic  spine. 

The  fundus  of  the  stomach  is  that  part  of  the  organ  which 
lies  above  and  to  the  left  of  the  cardia,  when  the  body  is  in  the 
supine  position.  It  bulges  upwards  into  the  left  cupola  of  the 
diaphragm,  and  its  upper  limit  reaches  the  fifth  rib  behind  the 
pericardium  and  apex  of  the  heart.  Distention  of  the  fundus 
with  gas  may  mechanically  produce  cardiac  discomfort  by 
direct  pressure.  In  the  erect  position,  the  upward  projection 
of  the  fundus  is  diminished,  and  it  tends  to  become  absorbed 
into  the  greater  curvature. 

The  long  axis  of  the  stomach  is  directed  downwards,  forwards, 
and  to  the  right.  Its  antero-superior  surface  is  directed  upwards 
and  forwards  and  lies  in  relation  to  the  left  half  of  the  diaphragm 
and  the  inferior  aspect  of  the  liver.  A  large  part  of  this  surface, 
which  lies  medial  to  the  left  costal  margin  and  below  the  inferior 
border  of  the  liver,  is  in  direct  contact  with  the  anterior  abdominal 
wall.  The  whole  surface  helps  to  form  the  posterior  wall  of  the 
supra-colic  compartment,  which  is  therefore  infected  by  the 
perforation  of  a  gastric  ulcer  situated  in  this  part  of  the  stomach. 

The  postero-inferior  surface  of  the  stomach  looks  downwards 
and  backwards,  and  is  in  relation  with  a  number  of  structures, 
which  constitute  the  stomach-bed.  In  its  upper  part,  this 
surface  is  in  contact  with  the  left  half  of  the  diaphragm,  the  left 
kidney,  the  left  suprarenal  gland,  and  the  spleen ;  its  lower 
part  rests  on  the  pancreas,  the  transverse  meso-colon,  and  the 
transverse  colon.  The  two  latter  structures  are  supported 
inferiorly  by  the  underlying  coils  of  small  intestine,  and  together 
with  the  pancreas,  they  form  a  ledge,  sloping  downwards  and 
forwards. 

The  Greater  Curvature  forms  the  anterior,  or  inferior,  border 
of  the  stomach.  With  the  body  in  the  horizontal  position,  it 

19 


290  THE  ABDOMEN  AND  PELVIS 

commences  on  the  fundus  (p.  289),  cuts  the  left  costal  margin 
at  the  tip  of  the  ninth  costal  cartilage,  descends  not  infrequently 
almost  to  the  umbilicus,  and  then  ascends  to  the  pylorus  (vide 
infra) ;  in  the  erect  posture  it  descends  to  the  umbilicus,  and 
sometimes  to  a  lower  level.  Along  the  greater  curvature,  the 
two  layers  of  peritoneum  which  clothe  the  stomach  pass  down- 
wards to  form  the  greater  omentum,  and  on  the  left  side  they 
pass  backwards  to  the  spleen  as  the  gastro-splenic  ligament. 

The  Lesser  Curvature  forms  the  upper  or  posterior  border 
of  the  stomach.  It  passes  downwards  and  to  the  right  from 
the  cardiac  orifice  to  the  pylorus,  curving  round  the  tuber 
omentale  of  the  liver.  It  can  be  mapped  out  on  the  surface  by 
a  line,  concave  upwards  and  to  the  right,  joining  these  two 
points.  In  the  erect  posture  this  line  becomes  more  nearly 
J -shaped  owing  to  the  descent  of  the  pylorus  and  the  fixation 
of  the  cardiac  end  of  the  stomach.  Along  the  lesser  curvature 
the  lesser  omentum  leaves  the  stomach  and  passes  to  the  liver 
and  diaphragm. 

The  distal  or  pyloric  portion  of  the  stomach  includes  the 
pyloric  antrum,  the  pyloric  canal,  and  the  pylorus.  The  pyloric 
antrum  is  a  secondary  dilatation  of  the  stomach  and  is  placed 
proximal  to  the  pyloric  canal.  The  latter  is  tubular  in  shape 
and  is  about  one  inch  long.  It  communicates  with  the  duodenum 
through  the  pylorus. 

With  the  body  in  the  supine  position  and  the  stomach 
moderately  distended,  the  Pylorus  lies  on  the  transpyloric  plane, 
half  an  inch  to  the  right  of  the  middle  line  ;  but  when  the  erect 
posture  is  adopted,  it  may  sink  down  to  the  level  of  the  third 
lumbar  vertebra.  In  Fig.  91,  where  the  radiogram  was  taken 
in  the  vertical  position,  the  pylorus  is  seen  at  that  level.  At 
a  subsequent  operation  it  was  found  that,  with  the  change  of 
posture,  it  had  ascended  to  the  transpyloric  plane. 

The  anterior  surface  of  the  pylorus  lies  in  contact  with  the 
liver,  which  hides  it  from  view  when  the  abdomen  is  opened. 

The  Position  of  the  Stomach  is  subject  to  wide  variations. 
It  is  affected  by  (i)  attitude,  (2)  respiration,  (3)  the  tonus  of  the 
anterior  abdominal  wall,  and  (4)  its  contents  and  those  of  the 
small  intestines  and  transverse  colon.  In  addition,  apart  from 
differences  due  to  pathological  conditions,  there  is  a  large  range 
of  individual  variation. 

When  the  body  assumes  the  erect  posture,  the  postero- 
inferior  surface  of  the  stomach  slides  downwards  and  forwards 


THE  ABDOMINAL  CAVITY  291 

on  the  sloping  ledge  which  supports  it.  This  movement  is 
rendered  possible  by  the  accompanying  slight  descent  of  the 
diaphragm  and  the  elasticity  and  loose  attachment  of  the  living 


FIG.  91. — Normal  Hypertonic  Stomach.  The  black  circle  is  on  the  umbilicus, 
and  the  pylorus  lies  to  the  right  side  of  the  body  of  the  third  lumbar 
vertebra. 

peritoneum  (p.  276).  At  the  same  time  the  pylorus  undergoes 
a  similar  change  of  position,  which  is  permitted  not  only  by  the 
two  factors  just  mentioned,  but  also  by  the  mobility  of  the 
first  inch  of  the  duodenum.  Owing  to  the  constancy  with  which 
this  downward  movement  has  been  observed  in  radiograms 


292  THE  ABDOMEN  AND   PELVIS 

taken  with  the  body  erect,  the  presence  of  the  pylorus  on  the 
transpyloric  plane  in  such  a  photograph  at  once  suggests  the 
probability  of  its  immobilisation  by  adhesions  in  the  pyloro-cystic 
region  (Fig.  92). 


FIG.  92.— High  Position  of  the  Pylorus.  At  the  subsequent  operation 
adhesions  were  found  fixing  the  pylorus  to  the  liver,  gall-bladder,  and 
neighbouring  structures.  The  black  circle  is  on  the  umbilicus  (fourth 
lumbar  vertebra). 

Traube's  Space  corresponds  to  that  part  of  the  stomach 
which  is  in  direct  contact  with  the  diaphragm  and  under  cover 
of  the  costal  margin.  It  is  bounded  (Fig.  150)  above  and  to  the 
right  by  the  inferior  margin  of  the  left  lobe  of  the  liver  ;  above, 


THE  ABDOMINAL  CAVITY  293 

by  the  lower  margin  of  the  left  lung  ;  and  behind,  by  the  anterior 
border  of  the  spleen.     Below,  it  is  limited  by  the  costal  margin. 


FIG.  93. Radiogram  of  Stomach,   showing     typical  J   outline.       The  black 

circle  lies  on  the  umbilicus.  The  bismuth  is  well  supported  by  the 
muscular  tonus,  and,  though  somewhat  low,  the  stomach  is  quite  normal. 
The  transverse  colon  contains  the  fragmented  bismuth  of  an  earlier 
bismuth  meal. 

The  upper  part  of  this  area  is  overlapped  by  the  left  pleural 
sac,  but  this  does  not  alter  the  tympanitic  stomach  note  which 
is  obtained  on  percussion.  Enlargement  of  the  left  lobe  of  the 


294  THE  ABDOMEN  AND  PELVIS 

liver  encroaches  on  Traube's  space  from  the  right  side  ;  enlarge- 
ment of  the  spleen  encroaches  on  it  from  the  left  side  ;  and 
pleuritic  effusions  encroach  upon  it  from  above. 

Structure  of  the  Stomach. — The  peritoneum  gives  the 
stomach  a  complete  serous  coat,  except  along  the  curvatures 
and  also  over  a  small  area  which  is  in  direct  contact  with  the 
diaphragm,  to  the  left  of  the  cardia.  The  muscular  coat  consists 
of  three  layers  of  involuntary  muscle :  an  outer  longitudinal,  an 
intermediate  circular,  and  an  inner  oblique  stratum.  The 
circular  layer  is  greatly  thickened  at  the  pylorus  to  form  a 
sphincter,  and  may,  in  infants,  give  rise  to  congenital  stenosis 
of  the  pylorus,  either  by  continued  spasm  or  by  actual 
hypertrophy.  The  mucous  coat  is  very  thick  and  highly  vascular, 
and  it  is  thrown  into  numerous  folds,  save  when  the  stomach  is 
distended. 

Radiographic  Examination  of  the  Stomach. — The  normal 
stomach  gives  a  J -shaped  shadow  in  radiograms  taken  in  the 
erect  posture  after  a  bismuth  meal.  The  longer  limb  of  the  J 
is  vertical  and  lies  to  the  left  of  the  middle  line.  The  bismuth, 
being  supported  by  the  tonicity  of  the  healthy  stomach  wall, 
reaches  a  higher  level  in  the  longer  than  it  does  in  the  shorter 
limb,  which  corresponds  to  the  pyloric  antrum  (Fig.  93).  In 
atony  of  the  stomach  this  support  is  withdrawn,  and  the  fluid 
adopts  a  uniform  horizontal  level. 

In  some  radiograms  a  small  cap-like  shadow  may  be  seen 
immediately  above  the  bismuth  in  the  pyloric  antrum  and 
separated  from  it  by  a  clear  area.  This  is  due  to  the  bismuth 
contained  in  the  first  inch  of  the  duodenum,  and  the  clear  area 
corresponds  to  the  pyloric  canal,  which  is  closed  by  the  contraction 
of  the  pyloric  sphincter. 

The  Examination  of  the  Living  Stomach.— When  the 
abdomen  has  been  opened,  preferably  in  the  median  plane 
above  the  umbilicus,  the  greater  omentum  is  usually  at  once 
exposed  and  the  transverse  colon  may  be  seen  shining  through 
it.  The  omentum  is  traced  upwards  till  the  greater  curvature 
is  recognised,  and  the  stomach  may  then  be  drawn  downwards 
and  towards  the  left  in  order  to  permit  the  pylorus  and  the  first 
part  of  the  duodenum  to  be  examined.  In  the  healthy  stomach 
the  walls  are  firm,  and  the  muscular  thickening  which  marks  the 
pyloro-duodenal  junction  renders  its  recognition  easy ;  but  in  the 
atonic  stomach  the  walls  are  flaccid  and  thinner,  and  the  pylorus 
is  more  difficult  to  identify.  In  these  cases  the  pyloric  veins 


THE  ABDOMINAL  CAVITY 


295 


which  run  across  the  anterior  surface  of  the  gut,  serve  as  a  guide 
to  the  site  of  the  pyloro-duodenal  junction  (Mayo).  The 
cardiac  end  and  fundus  can  be  examined,  but  owing  to  the 


pIG>  94. — Stomach  of  a  child,  showing  typical  J  outline.     The  black  circle 
is  on  the  umbilicus.      The  pyloric  antrum  is  somewhat  distended. 

fixation  of  the  former  they  cannot  easily  be  brought  into  view. 
By  drawing  the  stomach  downwards  and  to  the  right,  most  of 
the  greater  curvature  can  be  inspected. 


296  THE  ABDOMEN  AND  PELVIS 

In  searching  for  the  site  of  a  perforated  ulcer,  the  whole  of 
the  antero-superior  surface  of  the  stomach  and  the  anterior 
surface  of  the  first  part  of  the  duodenum  must  be  examined. 

If  gastric  contents  are  not  found  in  the  supra-colic  com- 
partment when  the  abdomen  is  opened,  the  postero-inferior 
surface  of  the  stomach  must  be  exposed  and  examined.  Before 
doing  so,  the  surgeon  explores  the  epiploic  foramen  (of  Winslow), 
and  if  it  is  found  closed  by  adhesions,  the  diagnosis  of  a  perforated 
ulcer  leaking  into  the  omental  bursa  may  be  made  with  some 
confidence.  In  order  to  gain  access  to  the  postero-inferior 
surface  of  the  stomach,  it  is  necessary  to  open  into  the  omental 
bursa.  This  can  be  done  by  carefully  tearing  through  the 
greater  omentum  about  three  inches  to  the  left  of  the  pylorus 
and  immediately  below  the  gastro-epiploic  vessels  (p.  297). 
The  greater  curvature  is  then  turned  forwards  and  upwards, 
and,  as  a  result,  a  large  part  of  the  postero-inferior  surface  of 
the  stomach  can  be  both  seen  and  felt  through  the  opening  in 
the  omentum.  The  cardia  and  the  upper  part  of  this  surface 
may  be  examined  by  tearing  through  the  thinnest  part  of  the 
lesser  omentum  and  everting  the  posterior  surface  of  the  stomach 
through  the  opening  thus  made. 

The  Arterial  Supply  of  the  stomach  is  derived,  either 
directly  or  indirectly,  from  the  cceliac  (axis)  artery,  which  arises 
from  the  aorta  just  above  the  neck  of  the  pancreas  and  at  once 
divides  into  (i)  the  left  gastric,  (2)  the  splenic,  and  (3)  the 
hepatic  arteries. 

1.  The  left    gastric    (coronary)    artery  passes  upwards  behind  the 
omental  bursa  to  the  cesophageal  opening  in  the  diaphragm.    There  it  comes 
into  contact  with  the  cardia,  and  having  given  off  one  or  two  ascending 
branches  to  the  oesophagus,  it  descends  along  the  lesser  curvature  from  left 
to  right.     It  usually  divides  into  two  parallel  branches,  which  anastomose 
with  the  right  gastric  (pyloric)  artery. 

2.  The  hepatic  artery  runs  to  the  right  along  the  upper  border  of  the 
pancreas,  turns  forwards  round  the  right  border  of  the  omental  bursa  just 
below  the  epiploic  foramen,  and  reaches  the  first  part  of  the  duodenum.     It 
then  turns  upwards  and  ascends  between  the  two  layers  of  the  lesser  omentum 
to  the  liver,  in  close  relation  to  the  bile-duct  and  portal  vein  (p.  314). 

As  the  hepatic  artery  passes  round  the  right  border  of  the  omental  bursa, 
it  gives  off  the  right  gastric,  which  runs  to  the  left  along  the  lesser  curvature 
and  anastomoses  with  the  left  gastric. 

The  gastro-duodenal  artery  arises  from  the  hepatic  at  the  upper  border 
of  the  first  part  of  the  duodenum.  It  descends  behind  the  duodenum  to  its 
lower  border  and  there  divides  into  the  superior  pancreatico-duodenal  (p.  324) 
and  the  right  gastro-epiploic  arteries.  The  latter  passes  to  the  left  along  the 
greater  curvature  of  the  stomach  and  anastomoses  with  the  left  gastro- 
epiploic. 

3.  The  splenic  artery  runs  to  the  left  behind  the  omental  bursa.    It 


THE  ABDOMINAL  CAVITY 


297 


has  a  tortuous  course  along  the  upper  border  of  the  pancreas  and  gives  off 
numerous  branches  to  that  viscus.  On  the  anterior  surface  of  the  left  kidney 
it  turns  forwards  between  the  two  layers  of  the  lieno-renal  ligament  and  ends 
in  the  spleen.  -  > 

The  short  gastric  and  the  left  gaslro-epiploic  arise  from  the  splenic  near  its 
termination  and  run  forwards  in  the  gastro-splenic  ligament  to  the  greater 
curvature.  The  short  gastric  arteries  are  distributed  to  the  fundus  ;  the 
left  gastro-epiploic  passes  to  the  right  along  the  greater  curvature  and  anasto- 
moses with  the  right  gastro-epiploic. 

The  stomach,  therefore,  is  supplied  directly  from  the  cceliac  artery  by  the 
left  gastric  (coronary),  and  indirectly  by  the  right  gastric  and  gastro-epiploic 
arteries  from  the  hepatic,  and  the  short  gastric  and  left  gastro-epiploic  arteries 


CEscphageal  branch 


Left  gastric  artery 
Left  inferior  phrenic  artery     \ 
Cceliac  glands 


Lesser  omer.tum,  cut  edges 


Hepatic  artery    .,. 


Coronary  glands 
/         Supra-pancreatic  glands 
/  Short  gastric  arteries 


Splenic 
branches 


Left  gastro- 
epiploic  artery 


Right  gastro- 
epiploic  artery 
Gastro-epiploic  gland 


Greater  omentum,  cut  edges 
FIG.  95. — The  Arteries  and  Lymph  Glands  of  the  Stomach.     The  course 
of  the  lymph  vessels  is  indicated  by  the  arrows. 

from  the  splenic  (Fig.  95).  The  branches'which  these  vessels  give  off  supply 
the  adjoining  areas  on  both  surfaces  of  the  stomach  and  run  at  right  angles 
to  its  axis.  Incisions  in  the  stomach  wall,  for  the  purpose  of  excising  gastric 
ulcers,  are  made  parallel  to  the  vessels  and,  therefore,  at  right  angles  to  the 
long  axis  of  the  stomach. 

The  gastro-epiploic  arteries  lie  between  the  two  anterior  layers 
of  the  greater  omentum.  They  are  distinctly  tortuous  and  are 
placed  about  half  an  inch  from  the  greater  curvature.  By  this 
arrangement  the  vessels  are  not  subjected  to  pressure  or 
stretching  when  the  stomach  becomes  distended. 


298  THE  ABDOMEN  AND   PELVIS 

The  Veins  of  the  Stomach  correspond  to  the  arteries  and 
terminate  in  the  portal  vein,  or  in  the  two  large  vessels  which 
form  it,  viz.  the  superior  mesenteric  and  the  splenic.  At  the 
cardia,  the  coronary  vein  anastomoses  freely  with  the  cesophageal 
veins  through  the  cesophageal  opening  in  the  diaphragm.  In 
this  situation,  therefore,  an  important  communication  occurs 
between  the  portal  and  systemic  circulations,  and  the  veins  at 
the  inferior  end  of  the  oesophagus  consequently  become  enlarged 
and  varicose  in  portal  obstruction.  Their  rupture  gives  rise  to 
haematemesis  which  may  be  the  first  sign  of  the  condition. 

The  Nerve-supply  of  the  Stomach  is  derived  from  both 
vagi,  and  from  sympathetic  fibres  which  are  associated  with 
the  arteries  and  derived  from  the  cceliac  plexus.  The  sympathetic 
nerves  leave  the  spinal  medulla  in  the  mid-thoracic  region 
(T.  5-8).  Referred  pain  frequently  occurs  in  connection  with 
gastric  disorders,  and  its  site  is  most  commonly  the  epigastrium. 
The  afferent  impulses  from  the  viscus  are  such  that  a  "  focus  of 
irritation  "  (Mackenzie)  may  be  established  in  the  mid-thoracic 
region  of  the  spinal  medulla.  As  a  result  stimulation  of  the 
terminal  fibres  of  the  afferent  nerves  which  are  connected  with 
the  segment  or  segments  involved  produces  an  abnormal 
response.  In  this  way,  localised  hyperaesthetic  or  hyperalgesic 
areas  of  skin  and  muscle  may  be  explained.  As  the  proximal 
part  of  the  stomach  is  supplied  by  the  nerves  which  arise  from 
the  higher  segments  of  the  spinal  medulla,  the  situation  of 
these  areas  on  the  surface  of  the  body  should  give  an  indication 
of  the  site  of  the  gastric  lesion.  Thus  a  hyperaesthetic  area  due 
to  an  ulcer  near  the  cardia  should  be  in  the  upper  part  of  the 
epigastric  region  (T.  6,  Fig.  72),  whereas  a  similar  area  due  to 
a  lesion  near  the  pylorus  should  be  in  the  lower  part  of  the  same 
region  (T.  8). 

In  the  examination  of  patients  suffering  from  gastric  disorders, 
the  areas  supplied  by  the  posterior  rami  of  the  5th-8th  Th. 
nerves  should  also  be  tested,  as  hyperaesthesia  and  hyperalgesia 
of  the  skin  of  the  back  and  the  underlying  sacro-spinalis  muscle 
are  frequently  present. 

Examples  of  the  viscero-motor  reflex  (p.  251)  are  also 
commonly  found  in  gastric  mischief.  They  give  rise  to  localised 
areas  of  contraction  in  the  upper  parts  of  both  recti  (more 
especially  the  left)  and  also  in  the  sacro-spinalis. 

The  Lymph  Vessels  of  the  Stomach  anastomose  freely 
with  one  another  in  its  walls,  but  the  lymph  flow  passes  in 


THE  ABDOMINAL  CAVITY  299 

different  directions  from  three  areas,  which  may  be  roughly 
indicated  in  the  following  way.  A  line  is  drawn  from  the  highest 
point  on  the  fundus  downwards  and  to  the  right  to  the  pylorus 
so  as  to  divide  the  organ  into  an  upper,  larger,  and  a  lower, 
smaller  area.  The  latter  is  again  subdivided  by  a  line  drawn 
upwards  from  the  middle  of  the  greater  curvature. 

The  primary  lymph  glands  of  the  upper  area  are  (i)  the 
coronary  group,  and  (2)  the  supra-pyloric  lymph  gland.  The 
coronary  group  lies  between  the  two  layers  of  the  lesser  omentum, 
and  is  closely  associated  with  the  left  gastric  vessels,  while  the 
lymph  stream  flows  in  the  same  direction  as  the  coronary  vein 
as  far  as  the  cceliac  artery.  The  supra-pyloric  lymph  gland  lies 
immediately  above  the  pylorus  in  association  with  the  right 
gastric  vessels,  and  the  lymph  stream  in  this  small  area  follows 
the  course  of  the  hepatic  artery.  From  both  the  efferents  pass 
to  the  cceliac  lymph  glands,  which  therefore  constitute  the 
secondary  or  main  group  for  the  upper  area  of  the  stomach.  They 
lie  around  the  trunk  of  the  cceliac  (axis)  artery  and  belong  to 
the  pre-aortic  group  (Fig.  95). 

The  primary  lymph  glands  of  the  right  lower  area  lie  between 
the  two  anterior  layers  of  the  greater  omentum  in  relation  to 
the  right  gastro-epiploic  vessels.  They  form  the  inferior  gastric 
chain,  and  those  near  the  pylorus  are  termed  the  sub-  and  retro- 
pyloric  glands.  Their  efferents  accompany  the  gastro-duodenal 
and  hepatic  arteries  and  end  in  the  cceliac  group. 

The  primary  lymph  glands  of  the  left  lower  area  lie  along  the 
upper  border  of  the  body  and  tail  of  the  pancreas.  Their  affer- 
ents  from  the  stomach  reach  them  by  passing  through  the  gastro- 
splenic  ligament ;  their  efferents  terminate  in  the  cceliac  group. 

The  direction  of  the  lymph  flow  from  the  three  areas 
described  above  is  of  great  practical  importance  in  connection 
with  malignant  disease  of  the  stomach.  This  condition  usually 
begins  near  the  pylorus  and  spreads  upwards  along  the  lesser 
curvature  in  the  direction  of  the  lymph  flow.  Its  removal 
therefore  necessitates  the  excision  of  as  much  of  the  lesser 
curvature  as  possible,  and  a  not  inconsiderable  portion  of  the 
greater  curvature  as  well. 

Owing  to  the  direction  of  the  lymph  stream,  the  disease 
rarely  spreads  to  the  duodenum,  and  therefore  only  its  first 
inch  or  so  requires  to  be  removed.  In  addition,  the  coronary, 
supra-pyloric,  and  inferior  gastric  lymph  glands  must  be  taken 
away  in  order  to  minimise  the  chances  of  recurrence. 


300  THE  ABDOMEN  AND  PELVIS 

Pylorectomy.— The  feasibility  of  pylorectomy  or  partial 
gastrectomy  having  been  recognised,  the  first  step  in  the 
operation  consists  of  the  division  of  the  lesser  omentum  near 
the  liver.  It  is  then  stripped  away  with  gauze  in  a  downward 
direction,  care  being  taken  to  avoid  injury  to  the  important 
structures  in  its  right  free  margin.  The  first  part  of  the 
duodenum  is  separated  from  the  portal  vein  and  the  head  of  the 
pancreas  (Fig.  87),  and  rendered  freely  movable.  At  the 
same  time  the  gastro-duodenal  (or  right  gastro-epiploic)  and 
the  right  gastric  vessels  are  exposed,  ligatured,  and  divided. 
The  duodenum  is  then  cut  through  between  two  clamps,  about 
i  or  i£  inches  beyond  the  pylorus,  and  its  distal  stump  is 
invaginated.  Next,  the  stomach  is  drawn  downwards  and  to 
the  left,  and  the  left  gastric  vessels  are  ligatured  close  to  the 
cardia.  The  lower  blade  of  a  clamp  is  now  passed  through  the 
greater  omentum  below  the  gastro-epiploic  vessels  and  carried 
upwards  through  the  omental  bursa  behind  the  stomach.  The 
superficial  blade  follows  anteriorly,  and  the  clamp  is  then  fixed 
in  such  a  way  as  to  remove  as  much  of  the  lesser  curvature  and 
as  little  of  the  greater  as  may  be  necessary.  After  ligature  of 
the  left  gastro-epiploic  vessels,  the  area  thus  mapped  out  is 
removed  along  with  its  associated  lymph  glands.  The  proximal 
cut  surface  of  the  stomach  is  closed,  and  a  posterior  gastro- 
enterostomy  completes  the  operation. 

In  the  course  of  malignant  disease  of  the  lesser  curvature,  the 
cceliac  lymph  glands  are  involved  secondarily  to  the  coronary 
and  supra-pyloric,  and  the  infection  may  be  carried  down  into 
the  pelvis  by  retro-peritoneal  lymph  vessels.  Secondary 
deposits  frequently  occur  in  the  liver.  They  may  be  due  to  the 
primary  growth  ulcerating  into  the  gastric  veins  and  the  passage 
of  cancerous  emboli  along  the  portal  vein ;  or  the  spread  may 
be  by  the  lymph  vessels.  In  this  case  the  coronary  lymph 
glands  become  obstructed  by  the  disease,  and,  as  a  result,  stasis, 
or  a  reversal  of  the  direction  of  the  flow,  occurs  in  the  lymph 
vessels  which  they  receive  from  the  liver. 

If  cancer  cells  pass  along  the  efferents  of  the  cceliac  lymph 
glands  and  enter  the  thoracic  duct,  they  may  subsequently 
infect  the  left  lower  anterior  group  of  the  deep  cervical  lymph 
glands  (p.  133);  which  are  sometimes  found  enlarged  in  malignant 
disease  of  the  stomach.  From  the  thoracic  duct  the  cells  may 
pass  into  the  left  innominate  vein  and  so  be  deposited  in  any 
part  of  the  body. 


THE  ABDOMINAL  CAVITY  301 

Gastro-Enterostomy. — When  the  stomach  fails  to  empty 
itself  efficiently  owing  to  pyloric  obstruction,  atony,  or  for  any 
mechanical  reason,  the  condition  may  be  improved  by  the 
operation  of  gastro-enterostomy,  with  or  without  additional 
complete  closure  of  the  duodenum.  In  the  presence  of  gastric 
or  duodenal  ulceration  associated  with  hyperchlorhydria,  the 
same  operation  may  be  performed  to  provide  a  new  outlet  from 
the  stomach,  thus  giving  to  the  ulcer  the  necessary  rest  from 
irritation ;  at  the  same  time  it  permits  the  bile  to  enter  the 
stomach  and  neutralise  the  hyperacid  gastric  contents. 

The  operation  of  choice  is  the  method  known  as  "  Posterior, 
no  loop,  antiperistaltic  gastro  -  jejunostomy."  When  the 
abdomen  has  been  opened,  preferably  in  the  median  plane, 
the  duodeno-jejunal  flexure  and  the  first  few  inches  of  the 
jejunum  must  be  identified.  The  greater  omentum  and 
transverse  colon  are  drawn  out  of  the  abdomen  with  the  left 
hand,  until  the  transverse  meso-colon  is  rendered  tense,  and 
the  latter  is  then  traced  backwards  to  its  attachment  with  the 
right  hand.  On  the  left  side  of  the  vertebral  column  and 
immediately  below  the  transverse  meso-colon  the  fingers 
encounter  the  first  coil  of  the  jejunum  ;  this  is  withdrawn 
through  the  wound,  and  in  the  process  the  duodeno-jejunal 
flexure  is  recognised  by  its  fixation.  The  surgeon  then  makes 
an  opening  in  the  greater  omentum  below  the  gastro-epiploic 
vessels,  and,  passing  his  left  hand  into  the  omental  bursa,  holds 
the  transverse  meso-colon  tense.  With  his  right  hand  he  then 
divides  the  latter  fold  for  at  least  two  inches  in  a  vertical 
direction.  Through  this  opening,  which  is  made  to  the  left  of 
the  middle  colic  artery  (p.  338),  the  surgeon  passes  the  proximal 
piece  of  the  jejunum  into  the  omental  bursa  with  his  right  hand. 
Maintaining  the  gut  in  its  original  direction,  he  draws  it  out 
with  his  left  hand  through  the  opening  in  the  greater  omentum 
(Stiles).  A  long  intestinal  clamp  is  applied  along  the  extended 
loop  of  bowel,  after  it  has  been  emptied  by  massage.  At  this 
stage  the  transverse  colon  and  greater  omentum  are  replaced 
in  the  abdominal  cavity  and  the  postero-inferior  surface  of  the 
stomach  is  turned  out  through  the  opening  in  the  latter.  The 
site  for  anastomosis  is  selected,  preferably  the  most  dependent 
part  of  the  greater  curvature,  and  a  second  clamp  is  applied 
transversely  to  this  area  of  the  stomach.  The  anastomosis  is 
carried  out,  and  finally  allowed  to  drop  back  into  the  omental 
bursa.  After  the  opening  in  the  greater  omentum  has  been 


302  THE  ABDOMEN  AND  PELVIS 

closed,  the  transverse  colon  is  again  lifted  out  of  the  abdomen 
and  the  jejunum  is  lightly  drawn  upon  until  the  anastomosis 
appears  at  the  opening  in  the  transverse  meso-colon.  The 
margins  of  this  opening  are  stitched  to  the  posterior  wall  of  the 
stomach  or  to  the  jejunum.  This  hinders  the  latter  from  being 
retracted  through  the  opening  and  prevents  the  occurrence  of 
hernia  of  small  intestine  into  the  omental  bursa. 

It  is  important  to  remember  that  during  this  or  any  other 
intestinal  anastomosis  the  haemorrhage  from  the  wounded 
bowel  is  controlled  by  those  sutures  which  pierce  all  three  coats  ; 
they  must  therefore  be  kept  taut  until  the  suturing  is  completed. 
The  reasons  for  the  choice  of  the  method  described  above  may 
be  briefly  stated  as  follows  : 

1.  The  posterior  anastomosis  is  preferable  because,  in  the 
conditions  for  which  the  operation  is  performed,  the  most 
dependent  part  of  the  stomach  is  on  the  postero-inferior  surface 
near  the  greater  curvature. 

2.  The  union  of  the  proximal  part  of  the  jejunum   to  the 
stomach  without  any  loop  is  very  rarely  followed  by  the  formation 
of  kinks  or  spurs. 

3.  The  original  direction  and  position  of  the  first  coil  of  the 
jejunum,  which  is  directed  towards  the  left,  are  preserved  ;   the 
anastomosis  is  therefore  antiperistaltic. 

4.  The  anastomosis  is  carried  out  through  an  opening  in 
the  greater  omentum.    While  it  is  being  established,  all  the 
viscera  except  those  parts  immediately  concerned  in  the  suturing 
are  within  the  abdominal  cavity.    Thus  the  more  movable 
jejunum  is  approximated  to  the  less  movable  stomach  (Stiles). 

5.  Both  the  hands  of  the  assistant  are  left  free. 

It  may  sometimes  be  found  impossible  to  perform  the 
posterior  operation,  if  adhesions,  which  may  obliterate  the 
omental  bursa,  render  the  stomach  less  freely  movable  or  if 
the  transverse  meso-colon  is  too  short.  Under  these  circum- 
stances the  anterior  method  of  anastomosis  is  adopted. 

Anterior  Gastro-Enterostomy. — This  route  necessitates 
the  use  of  a  loop,  as  it  is  impossible  to  bring  the  proximal  end 
of  the  jejunum  into  contact  with  the  anterior  surface  of  the 
stomach  in  a  satisfactory  manner.  The  duodeno-jejunal  flexure 
is  found  and  the  gut  is  traced  distally  for  eighteen  or  twenty 
inches.  A  loop  of  jejunum  is  then  brought  upwards  in  front 
of  the  greater  omentum  and  sutured  to  the  anterior  surface  of 
the  stomach  near  the  greater  curvature.  The  loop  is  intentionally 


THE  ABDOMINAL  CAVITY  303 

made  longer  than  is  necessary;  in  order  to  guard  against 
subsequent  obstruction,  because,  as  a  general  rule,  the  patient 
puts  on  weight  after  this  operation,  and  much  fat  may  be 
deposited  in  the  greater  omentum. 

Occasionally  in  loop  operations  a  kink  or  spur  may  form 
and  obstruct  the  outlet  into  the  distal  limb  of  the  anastomosis. 
The  bile  collects  in  the  proximal  limb  and  together  with  the 
food  is  prevented  from  passing  onwards.  If  the  pylorus  is 
patent,  this  may  set  up  a  vicious  circle.  It  is  therefore  usual  to 
carry  out  entero-anastomosis  in  addition  to  the  loop  operations, 
and  the  jejunum  on  the  proximal  side  of  the  gastro-enterostomy 
is  joined  to  the  jejunum  on  the  distal  side.  This  allows  the  bile 
to  short-circuit  into  the  small  intestine  at  some  distance  from 
the  gastric  anastomosis. 

After  this  second  step,  peptic  ulceration  occasionally  occurs 
in  those  portions  of  the  jejunum  between  the  gastric  anastomosis 
and  the  entero-anastomosis,  since  in  this  area  the  hyperacid 
chyme  is  not  neutralised  by  the  alkaline  bile. 

Development  of  the  Stomach  and  the  Omental  Bursa  (Lesser  Sac). — 

The  first  indication  of  the  stomach  is  a  fusiform  dilatation,  which  appears 
in  the  caudal  part  of  the  foregut  during  the  fourth  week.  It  is  median  in 
position  and  is  moored  to  the  anterior  and  posterior  abdominal  walls  by  a 
ventral  and  a  dorsal  mesentery.  The  dorsal  aspect  of  the  stomach  grows 
more  rapidly  than  the  ventral,  and  the  lower  or  pyloric  end  is  first  thrust 
forwards  and  is  then  rotated  to  the  right  side.  In  this  way  what  was  origin - 
nlly  the  left  surface  of  the  stomach  now  becomes  anterior,  and  it  carries  the 
left  vagus  nerve  with  it.  The  rotation  of  the  stomach  produces  a  fossa 
between  it  and  the  dorsal  wall ;  this  is  the  site  of  the  omental  bursa. 

The  lower  part  of  the  dorsal  mesentery  of  the  stomach  grows  rapidly 
and  sags  downwards  into  the  abdomen,  converting  the  fossa  into  a  bursal 
sac  which  has  a  widely  open  mouth  looking  to  the  right.  At  the  same  time 
the  mesentery  of  the  duodenum  shortens  and  then  disappears,  so  that  the 
lower  margin  of  the  epiploic  foramen  becomes  defined. 

The  spleen  develops  as  a  condensation  of  the  mesoderm  between  the  two 
layers  of  the  dorsal  mesentery  in  its  upper  part  and  divides  it  into  the  gastro- 
splenic  and  lieno-renal  ligaments. 

The  Duodenum  extends  from  the  pylorus  to  the  duodeno- 
jejunal  flexure.  It  forms  a  C-shaped  bend,  which  encloses  the 
head  of  the  pancreas,  and  its  total  length  is  about  ten  inches. 

When  the  body  is  in  the  supine  position,  the  Superior  or 
First  Part  of  the  duodenum  passes  backwards  and  slightly 
upwards  from  the  pylorus  to  the  neck  of  the  gall-bladder,  and 
is  in  relation  to  the  inferior  surface  of  the  liver.  When  the 
body  is  in  the  erect  position,  this  part  passes  vertically  upwards 
owing  to  the  descent  of  the  pylorus  (p.  290),  and  the  level  of  the 


304  THE  ABDOMEN  AND  PELVIS 

first  flexure  of  the  duodenum  sinks  downwards,,  sometimes,  to 
the  second  lumbar  vertebra.  The  proximal  inch  or  less  of  the 
first  part  is  freely  movable  as  it  is  invested  by  the  same  two 
layers  of  peritoneum  as  enclose  the  stomach.  Its  upper  border 
is  related  to  the  lesser  omentum  and  the  right  gastric  (pyloric) 
artery,  and  its  lower  border  to  the  greater  omentum  and  the  right 
gastro-epiploic  artery.  Behind  it  lies  a  small  recess  of  the 
omental  bursa.  The  distal  inch  or  more  of  this  part  receives 
from  the  peritoneum  only  an  anterior  covering  so  that  its  range 
of  movement  depends  entirely  on  the  elasticity  or  looseness  of 
its  peritoneal  coat.  Its  posterior,  or  postero-medial,  surface  is 
in  immediate  relation  to  the  bile-duct,  portal  vein,  and  gastro- 
duodenal  artery,  while  the  inferior  vena  cava  is  separated  from 
it  by  these  structures  and  by  some  areolar  tissue  (Fig.  87). 

The  whole  of  the  antero-lateral  surface  of  the  first  part  of 
the  duodenum  lies  in  the  supra-colic  subdivision  of  the  peritoneal 
cavity.  This  aspect  is  the  commonest  site  of  duodenal  ulceration, 
and  perforation  will  primarily  infect  the  supra-colic  compartment. 
On  the  other  hand,  perforation  of  an  ulcer  on  the  postero-medial 
surface  will,  if  it  is  situated  close  to  the  pylorus,  at  once  involve 
the  omental  bursa;  but  if  it  is  placed  more  distal ly,  the  infection 
will  be  retroperitoneal  and  may  pass  up  along  the  inferior  vena 
cava  to  the  extra-peritoneal  subphrenic  area  (p.  310). 

As  the  closure  of  such  perforations  results  in  marked  narrowing 
of  the  lumen  of  the  gut,  gastro-enterostomy  is  usually  performed 
lest  complete  obstruction  should  follow. 

Mayo  has  suggested  that  the  frequency  with  which  duodenal 
ulcer  occurs  on  the  antero-lateral  wall  is  determined  by  the  fact 
that  the  over-acid  chyme,  as  it  is  squirted  through  the  pylorus, 
incessantly  impinges  on  this  wall  and  produces  repeated  minute 
traumata.  It  has  also  been  urged  that  the  area  in  question  is 
supplied  by  a  small  branch  from  the  hepatic  or  gastro-duodenal, 
and  that  its  terminal  twigs  are  end-arteries,  i.e.  do  not  anastomose 
with  other  vessels  in  the  neighbourhood.  Thrombosis  in  this 
artery,  therefore,  would  in  all  probability  give  rise  to  necrosis 
of  the  area  supplied  by  it.  In  childhood,  however,  the  anasto- 
mosis is  complete. 

The  Descending  or  Second  Portion  passes  downwards 
from  the  neck  of  the  gall-bladder  along  the  medial  border  of 
the  right  kidney  to  the  level  of  the  third  lumbar  vertebra,  lying 
in  front  of  the  hilum  of  the  kidney  and  the  commencement  of 
the  ureter.  It  is  crossed  anteriorly,  in  its  lower  part,  by  the 


THE  ABDOMINAL  CAVITY 


transverse  colon,  which  at  this  point  may  or  may  not  possess  a 
mesentery,  and  in  this  situation  the  peritoneum,  which  gives  it 
an  anterior  covering  only,  is  lifted  from  its  surface.  Above  the 
transverse  colon,  the  second  part  of  the  duodenum  lies  in  the 


Epiploic  foramen 


Cystic  artery 
Portal  trem 
Hepatic  artery 
Lesser  oir.entum 


Bile-duct 
-—  Right  gastric  artery 

—  Right  suprarenal  gla 

—  Peritoneum,  cut  edg( 


Head  of  pancreas 


—  Peritoneum,  cut  edg< 
—  —  Inferior  vena  cava 


—  Right  ureter 


FIG.  96.  — Exposure  of  the  Terminal  Part  of  the  Bile-Duct.  The  peritoneum 
has  been  incised  along  the  right  sides  of  the  right  colic  flexure  and  of  the 
duodenum.  The  duodenum  and  the  flexure  have  been  turned  downwards 
and  to  the  left,  exposing  the  posterior  surface  of  the  head  of  the  pancreas. 
A  small  window  has  been  made  in  the  anterior  layer  of  the  lesser  omentum 
at  its  right  border. 

supra-colic  compartment ;  below,  it  lies  in  the  right  infra-colic 
compartment  and  is  related  laterally  to  the  ascending  colon 
(Fig.  88).  The  head  of  the  pancreas  and  the  terminal  part  of 
the  bile-duct  are  related  to  its  medial  side. 

Owing  to  its  peritoneal  relations,  the  second  part  of  the 

20 


3o6  THE  ABDOMEN  AND  PELVIS 

duodenum  is  fixed  in  position.  In  retro-peritoneal  exploration 
of  the  lower  end  of  the  bile-duct  (p.  316)  it  must  be  rendered 
movable  so  that  it  can  be  turned  downwards,  forwards,  and  to 
the  left.  This  can  be  effected  by  incising  the  peritoneum  over 
the  right  kidney  along  the  lateral  border  of  the  upper  end  of 
the  second  part  of  the  duodenum  (Kocher). 

If  necessary,  this  incision  may  be  extended  downwards 
along  the  lateral  margin  of  the  right  colic  flexure  and  the 
ascending  colon.  The  duodenum  and  the  ascending  colon  can 
then  be  lifted  off  the  right  kidney  and  turned  to  the  left  (Fig. 
96).  In  freeing  the  duodenum,  the  right  renal  vessels  are 
exposed  as  they  lie  in  close  relation  to  its  posterior  surface 
(see  also  p.  316). 

The  Horizontal  or  Third  Part  of  the  duodenum  runs 
transversely  to  the  left  in  front  of  the  ureter,  the  inferior  vena 
cava,  and  the  aorta  to  end  at  the  left  side  of  the  third  lumbar 
vertebra.  It  lies  behind  the  peritoneum  in  the  right  infra-colic 
compartment,  but  at  its  termination  it  is  crossed  by  the  root 
of  the  mesentery.  The  superior  mesenteric  vessels  and  accom- 
panying nerves  run  downwards  over  its  anterior  surface  and 
enter  the  root  of  the  mesentery  (Fig.  88).  This  relationship 
is  of  great  importance  in  the  condition  of  enteroptosis.  The 
weight  of  the  small  intestine,  hanging  down  into  the  pelvis, 
stretches  the  superior  mesenteric  artery  tightly  across  the  third 
part  of  the  duodenum,  producing  obstruction  which  may  lead 
to  acute  dilatation  of  the  stomach. 

The  head  of  the  pancreas  lies  in  contact  with  the  upper 
border  of  this  part  of  the  duodenum ;  in  the  groove  between 
these  two  structures  the  inferior  pancreatico-duodenal  artery 
(p.  323)  runs  towards  the  right. 

The  Ascending  or  Fourth  Part  of  the  duodenum  runs 
upwards,  and  slightly  to  the  left,  to  the  duodeno-jejunal  flexure. 
Its  left  side  is  covered  by  the  peritoneum  on  the  posterior  wall 
of  the  left  infra-colic  compartment,  while  its  right  side  is  in 
contact  with  the  pancreas  and  the  aorta. 

At  the  left  side  of  the  second  lumbar  vertebra  the  fourth  part 
of  the  duodenum  bends  sharply  forwards,  downwards,  and  to 
the  left  to  form  the  Duodeno-Jejunal  Flexure.  This  bend  lies 
in  contact  with  the  inferior  surface  of  the  pancreas  immediately 
below  the  root  of  the  transverse  meso-colon.  It  can  be  found 
by  passing  the  hand  backwards  behind  the  greater  omentum  to 
the  posterior  abdominal  wall,  and  then  carrying  it  upwards  along 


THE  ABDOMINAL  CAVITY  307 

the  left  side  of  the  vertebral  column  until  the  fingers  are  caught 
in  the  loop  of  the  flexure  (see  also  p.  301). 

Duodenal  Peritoneal  Fossae. — In  the  region  of  the  duodeno-jejunal 
flexure  there  are  several  inconstant  fossae  which  require  description,  as  they 
may  be  responsible  for  strangulated  retro-peritoneal  hernias. 

1.  The  superior  duodenal  fossa  is  bounded  in  front  by  a  free  crescentic 
margin,  which  extends  to  the  left  for  about  one  inch  from  the  duodeno-jejunal 
flexure.     Its  mouth  looks  downwards,  while  its  cavity  passes  upwards  towards 
the  pancreas.    The  upper  part  of  the  inferior  mesenteric  vein  may  lie  along 
its  lateral  border  and  project  into  its  anterior  wall. 

2.  The  inferior  duodenal  fossa  is  at  a  lower  level  and  its  mouth  looks 
upwards.     Its  anterior  margin  is  about  one  inch  long  and  is  attached  medially 
to  the  fourth  part  of  the  duodenum. 

3.  The  paraduodenal  fossa,  when  present,  is  larger  than  the  others.     Its 
mouth  looks  medially,  and  its  free  crescentic  margin,  which  may  be  two  inches 
long,  may  unite  the  lateral  extremities  of  the  free  borders  of  the  superior  and 
inferior  fossae  when  they  are  also  present.    The  inferior  mesenteric  vein  runs 
upwards  in  its  anterior  wall,  and  the  ascending  branch  of  the  left  colic  artery 
(p.  340)  may  occupy  a  similar  position  or  may  lie  along  its  lateral  margin. 
When  a  hernia  enters  this  fossa  it  carries  its  sac  downwards  and  laterally 
behind  the  posterior  parietal  peritoneum  and  the  vessels  already  mentioned, 
but  in  front  of  the  left  ureter  or  kidney.    Should  strangulation  occur,  great 
care  must  be  taken  in  dividing  the  neck  of  the  sac  lest  the  inferior  mesenteric 
vein  or  the  left  colic  artery  be  injured  ;  the  neck  of  the  sac  should  be  incised 
in  a  downward  direction,  parallel  to  the  vessels. 

4.  The  retro-duodenal  fossa  lies  behind  the  flexure  on  the  anterior  aspect 
of  the  aorta  and  vertebral  column.     Its  mouth  looks  towards  the  left,  and 
so  when  all  four  fossae  are  present  their  margins  form  a  continuous  circular 
edge. 

Surface  Marking  of  the  Duodenum. — The  duodenum  can  now  be 
mapped  out  on  the  surface.  The  first  flexure  lies  a  little  above  the  trans- 
pyloric  plane  at  a  distance  of  1^-2  inches  from  the  middle  line.  The  second 
portion  descends  medial  to  the  right  lateral  line  and  extends  a  little  below 
the  subcostal  plane.  The  third  port-ion  crosses  the  middle  line  horizontally, 
and  the  fourth  ascends  to  the  duodeno-jejunal  flexure,  which  just  reaches 
the  transpyloric  plane,  one  inch  to  the  left  of  the  middle  line. 

The  Liver  occupies  most  of  the  right  hypochondriac  and 
epigastric  regions.  It  is  roughly  pyramidal  in  shape,  its  base 
being  directed  to  the  right  and  its  apex  lying  behind  the  fifth 
left  intercostal  space,  half  an  inch  medial  to  the  left  lateral  line. 

The  Anterior  Surface  of  the  liver  is  related  to  both  halves 
of  the  diaphragm,  and  in  the  middle  line  it  lies  in  direct  contact 
with  the  anterior  abdominal  wall,  occupying  the  upper  part  of 
the  subcostal  angle  (Fig.  97).  In  this  region  it  can  readily  be 
examined  by  palpation  and  percussion.  It  is  partially  over- 
lapped by  the  right  lung  and  pleura  and,  under  cover  of  the  left 
costal  margin,  by  the  left  pleura  and,  to  a  slight  extent,  by  the 
pericardium  (Fig.  97).  Its  upper  border  can  be  mapped  out 
by  a  line  drawn  from  a  point  on  the  fifth  right  rib  half  an  inch 
medial  to  the  right  lateral  line,  to  a  second  point  in  the  fifth 

20  « 


3o8 


THE  ABDOMEN  AND  PELVIS 


left  interspace  half  an  inch  medial  to  the  left  lateral  line.  This 
line  curves  downwards  slightly  at  its  centre  and  crosses  the 
median  plane  at  the  xiphi-sternal  junction.  The  inferior  border 
of  the  anterior  surface  of  the  liver  extends  upwards  from  the 
tip  of  the  tenth  right  to  the  tip  of  the  eighth  left  costal  cartilage, 
crossing  the  middle  line  at  the  transpyloric  plane,  and  then 


FIG.  97. — Surface  Relations  of  the  Liver,  Stomach,  Lungs,  Heart 

and  Pleural  Sacs. 

Blue  line  =  outline  of  lung.  Dotted  blue  line  =  lines  of  pleural  reflection. 
Fine  black  line  =  heart  and  great  vessels.  Heavy  black  line  —  liver.  Dotted 
black  line  =  stomach. 

ascends  to  join  the  upper  border.  The  right  border  of  this 
surface  can  be  indicated  by  joining  the  right  extremities  of  the 
superior  and  inferior  borders  by  means  of  a  line  which  is  gently 
convex  to  the  right. 

Tropical  abscess  of  the  liver  may  point  on  the  anterior 
surface,  and  can  then  be  exposed  by  an  oblique  incision  just 
below  the  right  costal  margin.  If  necessary,  portions  of  the 


THE  ABDOMINAL  CAVITY  309 

eighth  and  ninth  costal  cartilages  may  be  resected,  but  the 
seventh  must  be  left  in  situ  on  account  of  the  danger  of  opening 
into  the  right  pleural  sac  (Fig.  97). 

The  Right  Lateral  Surface  of  the  liver  lies  under  cover  of 
the  seventh,  eighth,  ninth,  tenth,  and  eleventh  ribs,  and  extends 
a  little  below  the  costal  margin  in  the  mid-axillary  line.  It 
lies  in  contact  with  the  diaphragm,  and  is  overlapped  by  the 
right  pleura  in  rather  more  than  its  upper  two-thirds  (Fig.  151). 
It  is  entirely  covered  by  peritoneum,  and  a  recess  of  the 
greater  sac  extends  upwards  between  it  and  the  diaphragm. 

Solitary  abscess  of  the  liver  is  commonly  situated  near 
the  upper  surface  of  the  right  lobe,  and  as  it  enlarges  it  displaces 
the  diaphragm  in  an  upward  direction.  Evacuation  of  a  liver 
abscess  is  carried  out  from  the  right  side  by  means  of  a  curved 
incision,  convex  downwards,  which  is  planned  so  as  to  expose  the 
eighth  and  ninth  ribs  and  the  adjoining  intercostal  spaces.  The 
flap,  which  consists  of  skin  and  fasciae,  is  turned  upwards,  and 
a  portion  of  one  or  both  of  the  ribs  exposed  is  resected  sub- 
periosteafly.  The  periosteum  and  the  costal  pleura  on  its 
deep  surface  are  then  incised.  Usually  the  pleural  sac  in  this 
situation  is  found  obliterated  by  adhesions,  but  if  not,  the  cavity 
must  be  shut  off  by  suturing  the  upper  cut  margin  of  the  costal 
pleura  to  the  diaphragmatic  pleura.  It  will  probably  be 
necessary  to  ligature  the  intercostal  vessels  of  the  space  below 
the  rib  excised.  An  incision  is  then  made  through  the  diaphragm 
into  the  liver,  to  which  it  is  generally  firmly  adherent.  The 
adhesions,  which  are  due  to  perihepatitis,  entirely  obliterate 
the  peritoneal  recess,  which  separates  the  liver  from  the 
diaphragm.  Sinus  forceps  can  now  be  thrust  through  the  liver 
substance  into  the  abscess  cavity.  A  drainage  tube  may  be 
inserted  and  brought  to  the  surface  through  a  stab  wound  in 
the  flap,  so  that  the  original  incision  can  be  closed. 

The  Superior  Surface  of  the  liver  is  in  contact  with  the  dia- 
phragm, and  both  are  covered  by  peritoneum.  It  is  related  above 
to  both  lungs  and  pleural  sacs,  and  to  the  heart  and  pericardium. 

When  a  liver  abscess  ruptures  spontaneously  it  usually  does 
so  through  the  superior  surface,  after  it  has  become  adherent 
to  the  diaphragm.  It  thus  enters  the  pleural  sac  and  gives  rise 
to  an  empyaema.  It  sometimes  happens  that  adhesions  have 
fixed  the  basal  surface  of  the  lung  to  the  diaphragmatic  pleura, 
and  in  these  cases  the  pus  ruptures  into  the  lung,  being  sub- 
sequently evacuated  by  coughing. 

206 


3io  THE  ABDOMEN  AND  PELVIS 

The  Posterior  Surface  of  the  liver  is  in  contact  with  the 
inferior  vena  cava  and  the  diaphragm,  and  lies  in  front  of  the 
lower  thoracic  vertebrae.  The  peritoneum  on  the  superior 
surface  is  not  continued  over  the  posterior  surface,  but  is  reflected 
on  to  the  diaphragm,  forming  the  upper  or  anterior  layer  of  the 
coronary  ligament.  Since  the  peritoneum  on  the  inferior  surface 
of  the  right  lobe  is  reflected  on  to  the  kidney  as  the  hepato-renal 
(posterior  layer  of  coronary)  ligament,  the  right  half  of  the 
posterior  surface  is  devoid  of  any  peritoneal  covering.  It  is 
known  as  the  "  bare  area  "  and  is  in  direct  contact  with  the 
diaphragm.  The  bare  area  of  the  liver  is  the  site  of  extra- 
peritoneal  subphrenic  abscesses,  which  result  from  the  upward 
spread  of  .pus  from  retro-peritoneal  abscesses  on  the  right  side 
of  the  abdomen. 

The  Inferior  Surface  of  the  liver  is  divided  into  a  large 
right  and  a  smaller  left  lobe  by  the  fossa  for  the  umbilical  vein, 
which  extends  from  the  inferior  border  of  the  liver  to  the  left 
extremity  of  the  porta  hepatis  (transverse  fissure}.  The  porta  is 
placed  transversely  on  the  inferior  surface,  and  its  margins 
receive  the  attachment  of  the  lesser  omentum.  From  its  right 
extremity  the  fossa  for  the  gall-bladder  extends  forwards  to  the 
inferior  border  of  the  liver.  In  this  way  a  rectangular  area  is 
defined,  which  lies  in  contact  with  the  pylorus  and  the  com- 
mencement of  the  duodenum. 

The  inferior  surface  of  the  left  lobe  is  related  to  the  antero- 
superior  surface  of  the  stomach.  The  right  lobe  is  related  to 
the  right  kidney  posteriorly,  to  the  right  colic  flexure  anteriorly, 
and  to  the  gall-bladder  and  the  duodenum  medially. 

Tropical  abscess  of  the  liver  occasionally  points  on  the 
inferior  surface,  and  may  rupture  into  the  right  colic  flexure. 

Blood-vessels  of  the  Liver. — The  liver  receives  its  blood- 
supply  from  both  the  hepatic  artery  (p.  296)  and  the  portal  vein, 
and  after  circulating  through  the  liver  the  blood  is  returned 
to  the  inferior  vena  cava  by  the  hepatic  veins. 

The  Portal  Vein  brings  to  the  liver  the  blood  which  has 
already  passed  through  the  capillaries  of  (i)  the  whole  abdominal 
alimentary  canal,  except  the  lower  end  of  the  rectum  and  the 
anal  canal,  (2)  the  spleen,  (3)  the  pancreas,  and  (4)  the  gall- 
bladder. Portal  obstruction,  therefore,  whether  due  to  direct 
pressure  on  the  portal  vein  or  its  branches,  or  to  backward 
pressure  from  the  heart,  will  produce  venous  congestion  in  all 
these  organs,  with  enlargement  of  the  spleen  and  gastro-intestinal 


THE  ABDOMINAL  CAVITY  311 

disturbance.  Serum  transudation  occurs  (i)  into  the  stomach,, 
giving  rise  to  the  morning  sickness  of  alcoholic  cirrhosis ;  (2)  into 
the  intestines,  causing  diarrhoea;  and  (3), .into  the  peritoneal 
cavity,  giving  rise  to  ascites. 

Certain  channels  of  anastomosis  exist  between  the  portal  and 
the  systemic  circulation,  (i)  At  the  lower  end  of  the  oesophagus, 
the  left  gastric  veins  communicate  with  the  cesophageal  veins. 
In  portal  obstruction  these  veins  become  varicose  and  may 
rupture,  causing  hsematemesis.  (2)  At  the  lower  end  of  the 
rectum  the  superior,  middle,  and  inferior  haemorrhoidal  veins 
communicate  freely.  They  become  varicose  in  portal  obstruction 
and  give  rise  to  internal  haemorrhoids,  which  may  act  as  a 
"  safety  valve  "  to  the  venous  congestion.  In  cases  of  internal 
haemorrhoids  the  possibility  of  portal  obstruction  must  be 
excluded  before  operation  is  advised.  (3)  The  connections  of 
the  para-umbilical  vein  have  been  discussed  on  p.  243.  (4)  The 
lumbar  veins  on  the  posterior  abdominal  wall  communicate 
with  the  mesenteric  veins.  (5)  The  veins  on  the  "  bare  area  " 
of  the  liver  communicate  with  those  on  the  inferior  surface  of 
the  diaphragm. 

These  natural  routes  seldom  suffice  to  establish  compensation, 
and  the  Talma- M orison  operation  aims  at  the  production  of 
artificial  anastomoses  between  the  portal  and  the  systemic 
veins.  The  opposing  peritoneal  surfaces  of  the  liver,  spleen 
(portal  circulation),  diaphragm,  and  anterior  abdominal  wall 
(systemic  circulation)  are  greatly  irritated  to  encourage  the 
formation  of  adhesions.  In  addition,  the  greater  omentum 
(portal  circulation)  is  fastened  to  the  peritoneum  of  the  anterior 
abdominal  wall  (systemic  circulation)  by  a  series  of  stitches. 

Development  of  the  Liver. — The  liver  is  developed  from  a  hollow 
bud  which  grows  upwards  from  the  duodenum  into  the  septum  transversum 
(the  forerunner  of  the  diaphragm).  The  bud  subdivides  into  two,  of  which 
one  forms  the  gall-bladder  and  cystic  duct  and  the  other  gives  rise  to  the  liver 
substance.  The  liver  grows  downwards  with  great  rapidity  into  the  ventral 
mesentery  of  the  stomach,  which  it  subdivides  into  the  falciform  ligament 
and  the  lesser  omentum.  The  proximal  end  of  the  original  outgrowth 
remains  as  the  bile-duct  and  retains  its  connection  with  the  duodenum. 

The  Gall-Bladder  lies  in  a  fossa  on  the  inferior  surface 
of  the  right  lobe  of  the  liver.  It  is  covered  on  its  inferior  surface 
by  peritoneum  which  binds  it  closely  to  the  liver,  but  its  fundus 
may  project  beyond  the  lower  margin  of  that  organ  and  it  then 
receives  a  complete  investment.  The  long  axis  of  the  gall- 


312  THE  ABDOMEN  AND  PELVIS 

bladder  is  directed  upwards,  backwards,  and  medially  towards 
the  porta  (hilum)  of  the  liver,  where  it  becomes  narrowed  to 
form  the  cystic  duct.  On  its  medial  side  and  inferiorly  lie 
the  first  part  and  the  commencement  of  the  second  part  of  the 
duodenum ;  below  and  to  its  lateral  side  it  is  in  relation  to 
the  right  colic  flexure  and  the  commencement  of  the  transverse 
colon.  After  prolonged  cholecystitis,  it  may  be  united  to  these 
viscera  by  dense  adhesions,  and  occasionally  gall-stones  may 
ulcerate  through  its  wall  and  be  discharged  into  the  intestinal 
canal. 

The  cystic  artery  arises  from  the  right  terminal  branch  of  the 
hepatic  and  runs  to  the  right,  crossing  in  front  of  the  common 
hepatic  duct.  It  divides  into  a  superficial  branch  which 
supplies  the  inferior  surface  of  the  gall-bladder,  and  a  deep 
branch  which  ramifies  between  its  upper  surface  and  the  liver. 
The  cystic  vein  joins  the  vena  portse. 

Cholecystectomy. — Ligation  of  the  cystic  artery  and  duct 
constitutes  the  first  step  in  cholecystectomy.  This  is  carried 
out  close  to  the  origin  of  the  vessel  in  order  to  prevent  the 
haemorrhage  which  would  otherwise  occur  when  the  gall-bladder 
is  stripped  from  its  bed.  The  peritoneum  is  then  incised  along 
the  inferior  surface  of  the  gall-bladder  and  separated  from  it. 
After  the  viscus  has  been  freed  from  the  liver  and  excised,  the 
cut  edges  of  the  peritoneum  are  united  over  the  exposed  area 
of  liver  substance. 

Pancreatitis  may  accompany  or  follow  cholecystitis,  and 
produce  jaundice  by  pressure  on  the  bile-duct.  On  this  account 
the  gall-bladder  is  retained  if  at  all  possible,  for  cholecyst- 
enterostomy  may  subsequently  be  necessary  in  order  to  relieve 
the  condition. 

The  Nerve-Supply  of  the  Gall-Bladder  is  derived  from 
(1}  the  right  phrenic  (C.  3,  4,  and  5),  (2)  the  vagus,  and  (j)  the 
cceliac  sympathetic  plexus  (Th.  7-9).  The  repeated  attempts 
of  the  gall-bladder  to  expel  calculi  into  the  cystic  duct  give  rise 
to  referred  pain,  which  is  commonly  felt  in  the  right  half  of  the 
epigastrium,  but  severe  pain  is  sometimes  experienced  over 
the  right  shoulder  or  in  the  posterior  cervical  region.  In  both 
the  latter  cases  the  afferent  stimulus  does  not  pass  via  the 
sympathetic  but  by  the  phrenic  nerve.  The  viscero-motor 
reflex  is  frequently  present  in  the  upper  part  of  the  right  rectus. 
These  attacks  of  biliary  colic  cease  when  the  stone  has  accom- 
plished its  journey  along  the  bile-duct  into  the  duodenum,  or 


THE  ABDOMINAL  CAVITY  313 

when  the  expulsive  efforts  fail  and  the  stone  falls  back  again 
into  the  gall-bladder. 

As  the  centres  for  the  stomach  and  the,  gall-bladder  occupy 
the  same  segments  in  the  spinal  medulla,  and  since  both 
viscera  are  supplied  by  the  vagus,  the  symptoms  which  are 
due  to  viscero-sensory  and  viscero-motor  reflexes  are  very 
similar  in  the  two  cases.  Thus  in  ulceration  of  the  stomach 
the  stimulation  of  the  gastric  terminals  of  the  vagus  causes 
vomiting  on  the  ingestion  of  food.  In  diseases  of  the  gall- 
bladder the  afferent  impulses  along  the  vagus  may  set  up  a 
"  focus  of  irritation  "  in  the  medulla  oblongata,  so  that  the 
simple  stimulus  of  the  gastric  branches  of  the  same  nerve, 
caused  by  the  ingestion  of  food  into  the  healthy  stomach,  may 
elicit  an  abnormal  response  from  the  irritated  centre,  and  emesis 
results.  Errors  in  diagnosis,  therefore,  are  not  infrequent,  and 
are  easily  explained  in  the  light  of  the  nerve-supply  of  the  two 
viscera. 

The  Fundus  of  the  Gall-Bladder  may  be  mapped  out  on 
the  surface  in  the  angle  between  the  right  rectus  and  the  costal 
margin,  with  the  patient  in  the  supine  condition.  When  the 
gall-bladder  becomes  distended  it  enlarges  downwards  and 
medially,  giving  rise  to  a  movable  tumour,  which  may  be  mistaken 
for  a  floating  kidney.  Owing  to  its  peritoneal  connection  to 
the  liver,  the  tumour  always  returns  to  its  first  position  after 
being  displaced  by  manipulations,  and  this  feature  should  suffice 
to  determine  the  diagnosis. 

The  mucous  membrane  lining  its  interior  is  so  rich  in  mucus- 
secreting  glands  that,  when  the  cystic  duct  is  obstructed  by  an 
impacted  calculus,  the  gall-bladder  may  become  dilated  and  form 
a  mucocele.  This  obstruction  offers  no  hindrance  to  the  free 
passage  of  bile  into  the  duodenum,  and  therefore  cholecystitis 
may  be  present  without  an  associated  jaundice. 

In  the  event  of  permanent  occlusion  of  the  bile-duct  from 
pancreatitis,  malignant  disease,  or  stricture,  the  intense  jaundice 
and  the  itching  which  it  causes  may  be  relieved  by  the  operation 
of  cholecyst-enterostomy.  If  possible  the  duodenum  is  utilised, 
but,  failing  it,  good  results  follow  the  anastomosis  of  the  gall- 
bladder with  the  stomach,  right  colic  flexure,  or  the  transverse 
colon.  The  operation  is  carried  out  on  the  same  lines  as  gastro- 
enterostomy  or  entero-anastomosis. 

The  Cystic  Duct  is  about  i|  inches  long,  but  as  it  is  folded 
upon  itself  in  an  S-shaped  manner,  its  union  with  the  hepatic 


314  THE  ABDOMEN-  AND  PELVIS 

ducts  occurs  quite  close  to  the  neck  of  the  gall-bladder.  The 
lining  mucous  membrane  is  redundant  and  projects  into  the 
lumen  as  a  spiral  fold,  the  valve  of  Heister,  which  obstructs  the 
passage  of  a  probe  except  when  the  duct  is  greatly  enlarged 
owing  to  the  passage  of  stones  or  to  intermittent  obstruction 
of  the  common  duct. 

The  cystic  duct  may  be  examined  by  tracing  the  gall-bladder 
upwards,  backwards,  and  medially  to  the  porta  hepatis,  where 
it  is  associated  with  one  or  two  lymph  glands. 

The  Common  Hepatic  Duct  is  a  short  trunk  formed  by 
the  union  of  the  right  and  left  hepatic  ducts  in  the  porta  (hilum) 
of  the  liver. 

The  Bile-Duct  is  formed  immediately  below  the  porta  of 
the  liver  by  the  union  of  the  cystic  with  the  common  hepatic 
duct.  It  is  three  to  four  inches  long  and  passes  downwards  (i) 
in  the  lesser  omentum,  (2)  behind  the  first  part  of  the  duodenum, 
and  (3)  postero-lateral  to  the  head  of  the  pancreas,  to  terminate 
by  opening  into  the  second  part  of  the  duodenum. 

The  first  or  supra -duodenal  portion  of  the  bile-duct 
is  about  ij  inches  long.  It  descends  in  the  right  border  of  the 
lesser  omentum,  lying  in  front  of  the  portal  vein  and  to  the  right 
side  of  the  hepatic  artery.  Several  lymph  glands  are  closely 
related  to  the  bile-duct  at  its  commencement  and  near  its 
termination,  and  they  are  apt  to  become  enlarged  in  septic 
conditions  of  the  gall-bladder  and  bile-duct,  and  in  malignant 
disease  of  the  lesser  curvature  of  the  stomach  and  of  the  pancreas. 
When  enlarged  they  may  be  mistaken  for  impacted  gall-stones. 

The  surgical  approach  to  the  gall-bladder  (p.  252)  is  planned 
so  as  to  afford  sufficient  exposure  for  a  thorough  examination 
of  the  bile-passages  as  well.  After  the  gall-bladder  has  been 
dealt  with,  the  index  finger  of  the  left  hand  is  passed  along  its 
inferior  surface  and  introduced  into  the  epiploic  foramen  (of 
Winslow).  If  the  hepato-colic  ligament  (p.  279)  is  present,  it 
must  be  divided  to  improve  the  access.  The  supra-duodenal 
portion  of  the  bile-duct  may  then  be  palpated  between  the  left 
forefinger  and  thumb,  and  if  a  stone  is  detected  it  should  be 
"  milked  "  back  along  the  cystic  duct  into  the  gall-bladder. 
When  the  stone  is  impacted,  the  duct  is  hooked  forwards  to 
the  surface  and  incised  longitudinally  to  permit  of  its  extraction. 
Advantage  may  be  taken  of  this  opening  to  pass  a  probe  upwards 
to  explore  the  hepatic  ducts,  and  downwards  to  the  ampulla 
of  Vater. 


THE  ABDOMINAL  CAVITY  315 

The   second    or    retro -duodenal    part   of  the    bile-duct 

descends  behind  the  first  part  of  the  duodenum,  to  the  right  of 
the  portal  vein  and  in  front  of  the  inferior  vena  cava  (Fig.  87). 
Its  length,  usually  about  one  inch,  depends  upon  the  upward 
extent  of  the  head  of  the  pancreas.  In  order  to  examine  this 
part  of  the  bile-duct  the  finger  is  again  introduced  into  the 
epiploic  foramen  and  the  thumb  is  placed  on  the  antero-lateral 
aspect  of  the  first  part  of  the  duodenum.  When  the  two  are 
squeezed  together  the  presence  of  one  or  more  impacted  stones 
can  be  recognised.  It  may  be  necessary  to  expose  the  second 
part  of  the  bile-duct  (p.  306),  but  the  stone  can  sometimes  be 
manipulated  downwards  into  the  duodenum,  or  upwards  into 
the  first  part  of  the  bile-duct,  or  it  may  even  be  made  to  retrace 
its  course  along  the  cystic  duct  into  the  gall-bladder. 

The  third  or  pancreatic  portion  of  the  bile-duct  passes 
downwards  and  slightly  to  the  right  and  terminates  by  piercing 
the  postero-medial  aspect  of  the  second  part  of  the  duodenum 
about  its  middle.  It  is  about  i  J  inches  long  and  lies  in  a  groove 
on  the  postero-lateral  aspect  of  the  head  of  the  pancreas,  being 
sometimes  embedded  in  its  substance.  It  is  separated  from 
the  anterior  surface  of  the  inferior  vena  cava  by  some  fibrous 
tissue.  The  superior  pancreatico-duodenal  artery  lies  first  to 
the  right  side  of  the  bile-duct  and  then  crosses  in  front  of  its 
lower  end.  Very  often,  however,  the  artery  passes  behind  the 
duct,  and  in  these  cases  may  give  rise  to  haemorrhage  when 
the  pancreatic  portion  is  being  exposed.  In  this  operation 
haemorrhage  may  also  be  caused  by  injury  of  a  vein,  which  issues 
from  the  posterior  aspect  of  the  head  of  the  pancreas  and  runs 
upwards  and  medially,  along  the  medial  side  of  the  pancreatic 
part  of  the  bile-duct,  to  join  the  portal  vein.  As  the  bile-duct 
enters  the  wall  of  the  duodenum  it  is  joined,  on  its  left  side,  by 
the  pancreatic  duct,  and  the  two  open  into  a  dilatation  of  the 
canal — the  ampulla  of  Vater — which  lies  partly  within  the  wall 
(Fig.  98).  The  opening  from  the  ampulla  into  the  duodenum  is 
placed  on  the  duodenal  (bile)  papilla,  and  is  so  small  that  gall- 
stones, which  have  passed  along  the  whole  length  of  the  cystic 
and  bile  ducts,  often  become  impacted  in  the  ampulla.  When 
this  occurs,  the  pancreatic  secretion  as  well  as  the  bile  may  be 
prevented  from  entering  the  duodenum,  unless  a  communication 
exists  between  the  main  pancreatic  and  the  accessory  duct 
(p.  319).  In  addition,  septic  infection,  which  commonly  exists 
in  the  presence  of  gall-stones,  is  apt  to  spread  along  the  pancreatic 


316  THE  ABDOMEN  AND  PELVIS 

duct  and  cause  pancreatitis.  The  bile-duct  narrows  slightly 
just  before  opening  into  the  ampulla  of  Vater,  and  stones  may 
become  impacted  in  this  situation,  but  in  this  case  the  pancreas 
is  not  so  likely  to  be  affected. 

Considerable  variation  exists  in  the  method  of  termination  oj 
the  pancreatic  and  bile  ducts,  (i)  The  two  unite,  but  the  ampulla 
of  Vater  is  absent.  (2)  The  two  open  independently  into  the 
duodenum,  either  on  the  summit  of  a  small  papilla,  or  at  the 
bottom  of  a  slight  depression.  In  this  case  the  impaction  of  a 
stone  in  the  bile-duct  does  not  produce  symptoms  of  pancreatic 
obstruction  (Fig.  98). 

The  pancreatic  part  of  the  bile-duct  may  be  examined  by 


in 


IV 


FIG.  98. 


-Diagrams  to  show  the  Varying  Modes  of  Termination  of  the 
Bile-Duct  and  the  Pancreatic  Duct. 


I    shows   the   normal   arrangement,    with   the   accessory  pancreatic  duct 
opening  independently  into  the  duodenum  at  a  higher  level. 

gently  pressing  the  second  part  of  the  duodenum  against  the 
right  side  of  the  vertebral  column,  but  if  the  head  of  the  pancreas 
is  enlarged  and  hard  owing  to  chronic  pancreatitis,  great  difficulty 
may  be  experienced  in  determining  whether  a  stone  is  present 
or  not.  To  expose  this  part  of  the  duct,  it  is  necessary  to  free  the 
second  part  of  the  duodenum  and  turn  it  forwards  and  to  the 
left  (p.  306).  At  the  same  time  the  head  of  the  pancreas  is 
carefully  separated  from  the  inferior  vena  cava  and  exposed  to 
view.  The  bile-duct  is  then  found  at  the  upper  border  of  the 
first  part  of  the  duodenum,  traced  downwards  and  freed  from 
the  pancreas.  At  this  stage  some  haemorrhage  may  occur  from 
cut  branches  of  the  superior  pancreatico  -  duodenal  vessels. 
After  removal  of  the  stone,  satisfactory  drainage  of  the  region 


THE  ABDOMINAL  CAVITY  317 

can  be  obtained  by  bringing  out  a  tube  in  the  right  loin  through 
the  lumbar  triangle  (of  Petit),  lateral  to  the  right  kidney,  and  the 
displaced  viscera  may  then  be  returned  to  thejr  original  positions. 

When  a  stone  is  impacted  in  the  ampulla  of  Vater,  a  more 
direct  approach  is  obtained  by  the  trans-duodenal  route.  A 
vertical  incision  is  made  in  the  supra-colic  portion  of  the  second 
part  of  the  duodenum,  and  the  stone  can  then  be  felt  under  the 
mucous  coat  of  the  postero-medial  wall.  The  orifice  of  the 
duodenal  papilla  lies  under  cover  of  one  of  the  plicae  circulares 
(valvulse  conniventes),  and  may  sometimes  be  located  by 
expressing  some  bile  from  it. 

The  exit  from  the  ampulla  of  Vater  is  then  enlarged  by 
slitting  it  in  an  upward  direction  until  it  permits  of  the  extraction 
of  the  stone. 

The  bile-duct  may  be  exposed  to  considerable  pressure  from 
the  head  of  the  pancreas  in  malignant  disease  or  in  chronic 
pancreatitis,  on  account  of  the  intimate  relation  of  the  two 
structures.  In  the  former,  the  steadily  increasing  obstruction 
is  accompanied  by  the  gradual  onset  of  jaundice,  which  slowly 
but  surely  increases  in  intensity ;  in  chronic  pancreatitis  the 
colour  changes  are  more  irregular.  It  sometimes  happens  that 
a  calculus  ulcerates  from  the  duct  into  the  gland  and  constitutes 
a  foreign  body  in  the  head  of  the  pancreas,  which  can  only  be 
removed  by  incising  the  gland. 

The  Pancreas  is  an  elongated  gland,  which  crosses  the 
posterior  abdominal  wall  from  right  to  left  with  an  upward 
inclination.  It  consists  of  a  head,  a  neck,  a  body  and  a  tail, 
and,  with  the  exception  of  the  tail,  which  usually  lies  between 
the  two  layers  of  the  lieno-renal  ligament,  it  is  entirely  retro- 
peritoneal. 

The  head  lies  in  the  concavity  of  the  duodenum  and  is 
covered  anteriorly  by  the  pylorus,  above,  and  the  transverse 
colon,  below.  Posteriorly,  it  rests  upon  the  inferior  vena  cava  and 
the  right  renal  vessels,  and  is  grooved  by  the  bile-duct  (p.  315). 

The  neck  passes  upwards  and  to  the  left  to  become  continuous 
with  the  body.  It  is  covered  anteriorly  by  the  peritoneum  on 
the  posterior  wall  of  the  omental  bursa  and  supports  the  pyloric 
end  of  the  stomach.  Behind  it  the  superior  mesenteric  and 
splenic  veins  unite  to  form  the  portal  vein. 

The  body  of  the  pancreas  crosses  the  middle  line  at  or  a 
little  below  the  transpyloric  plane.  It  is  somewhat  triangular 
on  section  and  consequently  possesses  three  surfaces.  The 


3i8  THE  ABDOMEN  AND  PELVIS 

anterior  surface  is  covered  by  the  peritoneum  on  the  posterior 
wall  of  the  omental  bursa  (Fig.  85)  and  forms  part  of  the 
stomach-bed.  The  inferior  surface  is  covered  by  the  peritoneum 
of  the  greater  sac  and  is  in  relation  to  both  infra-colic  compart- 
ments and  the  duodeno-jejunal  flexure.  These  two  surfaces 
are  separated  from  one  another  by  the  anterior  border  of  the 
gland,  along  which  the  two  layers  of  the  transverse  meso-colon 
separate  from  one  another  (Fig.  85).  The  posterior  surface 
crosses  in  front  of  the  aorta,  the  left  suprarenal  gland  and  the 
left  kidney  (Fig.  87),  and  is  partially  separated  from  all  of  these 
structures  by  the  splenic  vein. 

The  tail  of  the  pancreas  usually  lies  between  the  two  layers 
of  the  lieno-renal  ligament  and  is  related  to  the  left  colic  flexure, 
inferiorly. 

The  Pancreatic  Duct  commences  in  the  tail  and  traverses 
the  whole  gland  near  its  posterior  surface.  It  emerges  from 
the  right  border  of  the  head  and  opens  into  the  ampulla  of  Vater, 
together  with  the  bile  duct.  An  accessory  duct  drains  part  of 
the  head  and  opens  into  the  duodenum  above  the  ampulla.  It 
may  communicate  with  the  main  pancreatic  duct,  and  when  it 
does  so  it  may  convey  the  whole  of  the  pancreatic  secretion  to 
the  duodenum  in  the  event  of  obstruction  of  the  terminal  part 
of  the  main  duct  (p.  315).  When  the  obstruction  is  not  relieved 
in  this  way,  retention  cysts  may  arise  in  the  gland. 

Cysts  of  the  Pancreas  may  project  (i)  from  its  anterior  sur- 
face, (2)  from  its  anterior  border,  or  (3)  from  its  inferior  surface. 

(1)  Cysts  on  the  anterior  surface  of  the  gland  project  into 
the  omental  bursa.     As  they  enlarge,  they  may  push  the  lesser 
omentum  forwards  and  reach  the  anterior  abdominal  wall  above 
the  lesser  curvature ;    or  they  may  push  forwards  the  upper 
part  of  the  greater  omentum  and  reach  the  surface  below  the 
greater  curvature  but  above  the  transverse  colon. 

(2)  Cysts  which  appear  on  the  anterior  border  may  separate 
the  two  layers  of  the  transverse  meso-colon  and  thrust  the 
transverse  colon  before  them  to  the  surface.     In  this  condition 
the  dull  percussion  note  over  the  tumour  is  interrupted  by  the 
tympanitic  note  of  the  transverse  colon. 

(3)  Cysts  which  appear  on  the  inferior  surface  of  the  gland 
project  into  the  infra-colic  compartment  and  thrust  the  greater 
omentum   before   them.    They   come   into   contact   with   the 
anterior  abdominal  wall  below  the  transverse  colon. 

The  Arterial  Supply  of   the  Pancreas    is    derived    from 


THE  ABDOMINAL  CAVITY  319 

three  sources,  (i)  The  superior  pancreatico-duodenal,  a  branch 
of  the  gastro-duodenal  (p.  296),  and  (2)  the  inferior  pancreatico- 
duodenal,  a  branch  of  the  superior  mesenteric  (p.  323),  supply 
the  head  of  the  gland.  (3)  The  pancreatic  branches  of  the 
splenic  artery  supply  the  rest  of  the  gland. 

The  Veins  of  the  Pancreas  join  the  splenic  vein,  but  a  fairly 
large  vein  issues  from  the  dorsal  aspect  of  the  head  and  runs 
upwards,  to  the  left  of  the  bile-duct,  to  join  the  portal  vein. 
This  vessel  may  give  rise  to  haemorrhage  during  the  exposure  of 
the  third  part  of  the  bile-duct  (p.  315). 

Development  of  the  Pancreas.— The  pancreas  is  developed  from  two 
hollow  buds,  of  which  one  springs  from  the  ventral  and  the  other  from  the 
dorsal  aspect  of  the  duodenum.  The  ventral  bud  arises  at  the  same  point 
as  the  liver-bud,  but  it  only  forms  a  small  portion  of  the  head  of  the 
pancreas,  while  the  dorsal  bud  gives  rise  to  the  rest  of  the  head,  to  the 
neck,  body  and  tail  of  the  gland.  The  two  masses  of  cells  grow  into  the 
mesentery  of  the  duodenum  and  fuse  with  one  another.  Their  ducts  also 
unite  and,  as  growth  proceeds,  the  proximal  part  of  the  dorsal  duct  remains 
small,  so  that  the  main  adult  duct  is  derived  from  the  ventral  duct  and 
the  distal  part  of  the  dorsal  duct,  and  consequently  opens  into  the  ampulla 
of  Vater  in  common  with  the  bile-duct.  Although  small,  the  proximal 
part  of  the  dorsal  duct  persists  as  the  accessory  pancreatic  duct  and 
retains  its  original  connection  with  the  duodenum.  The  communication 
of  the  two  primitive  ducts  with  one  another  may  or  may  not  be  retained 
(see  p.  315). 

The  Spleen  lies  in  the  left  hypochondriac  region  under 
cover  of  the  ninth,  tenth,  and  eleventh  ribs,  and  its  long  axis 
corresponds  roughly  to  the  tenth.  It  is  almost  completely 
surrounded  by  peritoneum  and  projects  into  the  greater  sac 
between  the  stomach  and  the  lateral  part  of  the  left  kidney. 
It  is  attached  to  the  greater  curvature  of  the  stomach  by  the 
gastro-splenic  ligament,  and  to  the  anterior  surface  of  the  left 
kidney  by  the  lieno-renal  ligament  (Fig.  87).  The  postero- 
lateral  aspect  of  the  spleen  lies  in  contact  with  the  diaphragm, 
and  its  antero-medial  surface  is  related  to  the  stomach,  in  front, 
the  kidney,  behind,  and  the  left  colic  flexure  and  the  phrenico- 
colic  ligament,  below. 

The  diaphragmatic  surface  of  the  spleen  is  roughly 
triangular  in  shape,  and  its  apex  or  superior  angle  can  be 
indicated  on  the  dorsal  surface  of  the  body  at  a  point  i|  inches 
lateral  to  the  tenth  thoracic  spine.  Its  inferior  angle  lies 
opposite  the  eleventh  intercostal  space  about  3^  inches  lateral 
to  the  first  lumbar  spine,  and  its  anterior  angle  is  placed  on  the 
mid-axillary  line  in  the  ninth  intercostal  space  (Fig.  84).  When 
these  points  are  joined  to  one  another  by  lines  which  are  slightly 


320 


THE   ABDOMEN  AND  PELVIS 


convex  outwards,  the  surface   outline   of  the   diaphragmatic 
surface  of  the  spleen  is  obtained  (Stiles).     It  will  be  seen  from 


FIG.  99. — Dissection  to  expose  the  Spleen.  Portions  of  the  5th- nth  ribs 
have  been  resected.  A  part  of  the  lower  lobe  of  the  left  lung  and  a 
part  of  the  left  half  of  the  diaphragm  have  also  been  removed. 

Fig.  99  that  the  whole  of  this  surface  is  separated  by  the 
diaphragm  from  the  left  pleural  sac  ;  in  addition,  in  its  upper 
part  it  is  overlapped  by  the  inferior  margin  of  the  left  lung 


THE  ABDOMINAL  CAVITY  321 

(p.  292).  In  puncture  of  the  normal  spleen,  the  needle  must 
pass  through  the  muscular  wall,  the  pleural  sac,  the  diaphragm 
and  the  peritoneal  cavity  before  the  organ  is  reached. 

The  splenic  artery  has  already  been  described  (p.  296). 

The  splenic  vein  issues  from  the  hilUm  of  the  spleen  and 
is  at  once  joined  by  the  left  gastro-epiploic  veins  and  the  venae 
breves,  which  pass  from  the  stomach  between  the  two  layers 
of  the  gastro-splenic  ligament.  It  then  runs  backwards  in  the 
lieno-renal  ligament  to  the  posterior  abdominal  wall,  where  it 
turns  to  the  right  behind  the  pancreas.  It  receives  numerous 
pancreatic  veins,  and  is  joined,  near  its  termination,  by  the 
inferior  mesenteric  vein.  Behind  the  neck  of  the  pancreas  it 
is  joined  by  the  superior  mesenteric  vein,  and  the  two  together 
form  the  portal  vein.  Portal  obstruction,  therefore,  invariably 
gives  rise  to  venous  congestion  of  the  spleen  (p.  310). 

The  lymph  vessels  of  the  spleen  terminate  in  the  lymph 
glands  at  the  hilum.  From  these  splenic  glands  the  afferents 
pass  to  the  pancreatic  and  cceliac  lymph  glands. 

Splenic  Enlargement. — When  the  spleen  becomes  enlarged, 
in  malaria,  splenic  anaemia  and  other  diseases,  its  anterior 
border  projects  beyond  the  left  costal  margin  and  is  in  contact 
with  the  deep  surface  of  the  anterior  abdominal  wall.  Normally 
this  border  possesses  one  or  two  notches  or  indentations,  and  in 
splenic  enlargement  the  notches  become  more  pronounced.  On 
palpation  of  a  tumour  in  the  left  lumbar  region,  the  discovery  of  one 
or  more  notches  on  its  anterior  border  may  settle  the  diagnosis. 

The  direction  taken  by  the  enlarging  spleen  is  usually 
obliquely  downwards  and  medially,  as  the  phrenico-colic  ligament 
and  the  splenic  flexure  obstruct  its  enlargement  in  a  purely 
downward  direction. 

Splenectomy. — Owing  to  its  vascularity,  stab  wounds  or  rupture  of  the 
spleen  give  rise  to  severe  haemorrhage,  and  removal  of  the  organ  may  be 
necessary.  Good  access  is  obtained  by  an  incision  similar  to  that  described 
for  operations  on  the  gall-bladder  (p.  25  2),  but  on  the  opposite  side,  or  by  a 
long  vertical  incision  through  the  left  rectus.  Thereafter,  two  methods 
are  open  to  the  surgeon,  (i)  The  omental  bursa  is  opened  by  tearing 
through  the  greater  omentum  just  above  the  transverse  colon.  The  stomach 
is  retracted  upwards  and  the  peritoneum  is  cautiously  divided  at  the  upper 
border  of  the  pancreas.  The  splenic  artery  is  exposed  and  the  vein  is  found 
at  a  slightly  lower  level.  Both  vessels  are  tied  in  this  situation,  and  the 
haemorrhage  is  at  once  reduced.  The  gastro-splenic  ligament  may  now  be 
ligatured  and  divided  piece  by  piece.  When  the  lieno-renal  ligament  has  been 
similarly  treated,  the  spleen  can  be  removed. 

(2)  The  spleen  is  drawn  forwards  to  the  abdominal  wound,  and  the  left 
side  of  the  lieno-renal  ligament  is  exposed.  The  ligament  is  ligatured  and 
divided  piece  by  piece.  The  spleen  is  then  drawn  over  to  the  left  in  order 

21 


322  THE  ABDOMEN  AND  PELVIS 

that  the  same  procedure  may  be  carried  out  with  regard  to  the  gastro-splenic 
ligament. 

It  may  not  be  possible  to  carry  out  the  second  method  if  perisplenitis  has 
caused  adhesions  to  form  between  the  spleen  and  the  diaphragm. 

Small  Intestine. — The  freely  movable  part  of  the  small 
intestine  extends  from  the  duodeno-jejunal  flexure  to  the 
caecum.  The  upper  two-fifths  constitutes  the  jejunum  and 
the  lower  three-fifths  the  ileum,  but  there  is  no  definite  line  of 
demarcation.  These  two  parts  of  the  alimentary  canal  together 
measure  about  twenty-three  feet,  and  they  are  suspended  from 
the  posterior  abdominal  wall  by  the  mesentery,  which  gives 
them  an  almost  complete  investment  of  peritoneum.  The  coils 
of  the  jejunum  and  ileum  occupy  the  infra-colic  compartments 
and  the  pelvis,  and  are  usually  covered  over  by  the  greater 
omentum.  In  most  cases  the  first  loop  of  the  jejunum  can  be 
found  on  the  anterior  surface  of  the  left  kidney,  near  its  lower 
pole,  while  the  lowest  loop  of  the  ileum  lies  in  the  pelvis. 

The  Mesentery. — The  root  of  the  mesentery  begins  on  the 
anterior  surface  of  the  fourth  part  of  the  duodenum  in  front  of 
the  left  side  of  the  second  lumbar  vertebra,  and  extends  down- 
wards and  to  the  right.  It  crosses,  successively,  in  front  of 
the  third  part  of  the  duodenum,  the  aorta,  the  inferior  vena 
cava,  the  right  ureter  and  the  psoas  major,  and  terminates  in 
the  right  iliac  fossa  at  the  ileo-caecal  junction.  This  line  of 
attachment  is  only  six  or  seven  inches  in  length,  and,  in  order 
to  enclose  the  twenty-three  feet  of  intestine,  the  mesentery 
spreads  out  in  a  fan-shaped  manner  and  becomes  very  much 
pleated  near  the  gut.  Its  depth  varies,  being  as  much  as  seven 
or  eight  inches  at  its  deepest  part.  The  two  peritoneal  layers  of 
which  it  consists  contain  between  them  nerves,  blood-vessels, 
lymph  vessels  (lacteals)  and  glands,  and  a  varying  amount  of 
fat.  The  latter  is  more  thickly  deposited  along  the  root,  and  it 
diminishes  in  quantity  as  the  mesentery  is  traced  to  the  intestine. 
This  feature  is  much  better  marked  in  the  upper  than  in  the 
lower  end  of  the  mesentery,  and,  when  it  is  examined  near  the 
duodeno-jejunal  flexure,  semi-translucent  peritoneal  "  windows  " 
can  be  seen,  separated  from  one  another  by  branches  of 
the  superior  mesenteric  artery  (Fig.  100).  These  "  windows  " 
become  more  obscure  as  the  jejunum  is  traced  downwards,  and, 
in  the  lower  part  of  the  ileum,  they  cannot  be  distinguished 
owing  to  the  larger  deposition  of  fat  near  the  gut  (Fig.  101). 
By  the  examination  of  the  mesentery,  therefore,  it  may  be 


THE  ABDOMINAL  CAVITY 


323 


possible  to  determine  whether  a  loop  of  small  intestine,  drawn 
out  through  an  abdominal  wound,  belongs  to  the  upper  or  lower 
part  of  the  canal.  At  the  same  time  it  is  important  that  the 
surgeon  should  be  able  to  distinguish  the  proximal  from  the 
distal  end  of  such  a  loop.  If  its  mesentery  is  not  twisted  in 
any  way — this  can  be  ascertained  by  tracing  it  back  to  the 


FIG.  ioo. — A  Coil  from  the  upper  part  of  the  Jejunum.  The  peritoneum 
has  been  partially  removed  to  show  the  arterial  arcades.  Compare  the 
appearance  of  the  "windows"  and  the  disposition  of  the  fat  in  the 
mesentery  with  Fig.  101. 

vertebral  column — the  upper  or  left  end  of  the  loop  on  the  surface 
is  also  in  reality  its  proximal  end. 

The  Superior  Mesenteric  Artery  arises  from  the  aorta 
behind  the  pancreas  and  descends  in  front  of  the  third  part  of 
the  duodenum.  It  then  enters  the  root  of  the  mesentery  and 
runs  downwards  and  to  the  right  at  a  distance  of  about  half  an 
inch  from  the  posterior  abdominal  wall. 

Close  to  its  origin  it  gives  off  the  inferior  pancreatico-duodenal 
artery,  which  runs  to  the  right  between  the  head  of  the  pancreas 

21  a 


324 


THE  ABDOMEN  AND   PELVIS 


and  the  duodenum,  supplying  both  these  structures  and  anastom- 
osing with  the  superior  pancreatico-duodenal  (p.  296). 

The  intestinal  arteries  form  a  series  of  twelve  to  fifteen 
branches,  which  arise  from  the  left  side  of  the  superior  mesenteric 
and  pass  towards  the  jejunum  and  ileum.  They  break  up  into 
branches  which  unite  and  reunite  to  form  a  connected  series  of 
arcades,  which  are  more  complex  in  the  ileum  than  in  the 
jejunum  (Fig.  101).  From  the  terminal  arcades,  small  branches 
pass  to  the  mesenteric  border  of  the  gut  and  there  bifurcate. 


FIG.  101. — A  Coil  from  the  lower  part  of  the  Ileum.  The  peritoneum  has 
been  partially  removed  to  show  the  arterial  arcades.  Observe  how  the 
fat  in  the  mesentery  overlaps  the  gut,  and  compare  with  Fig.  100. 

In  the  intestinal  wall  they  run  parallel  to  the  circular  muscular 
coat,  at  first  in  the  subserous,  then  in  the  muscular,  and  finally 
in  the  submucous  coat. 

The  ileo-colic  (p.  333),  right  colic  (p.  336)  and  middle  colic 
arteries  (p.  336)  are  described  in  connection  with  the  large 
intestine. 

In  dividing  the  bowel,  previous  to  carrying  out  an 
anastomosis,  it  is  advisable  to  remove  less  of  the  mesenteric 
than  of  the  anti-mesenteric  border  in  order  that  the  retained 
cut  margin  may  have  a  good  blood-supply. 

The  lymph   vessels   of   the  jejunum  and    ileum  join    the 


THE  ABDOMINAL  CAVITY  325 

superior  mesenteric  lymph  glands,  which  lie  between  the  two 
layers  of  the  mesentery.  This  group  includes  a  large  number 
(100  to  200)  of  glands,  and  may  be  directly  infected  with 
tuberculosis  from  the  alimentary  canal,  When  they  break 
down  they  involve  one  or  both  of  the  infra-colic  compartments. 
Their  efferent s  join  the  pre-aortic  glands. 

In  the  walls  of  the  small  intestine  the  lymph  vessels  run  at 
right  angles  to  the  long  axis,  and  when  they  are  infected  from 
the  tuberculous  ulceration  of  an  aggregated  lymph  nodule  (Peyer's 
patch),  the  spread  of  the  disease  along  them  may  produce  a 
stricture  of  the  gut.  These  lymph  nodules  are  most  numerous 
in  the  terminal  part  of  the  ileum,  and  it  is  consequently  the 
commonest  site  for  tuberculous  stricture.  On  this  account,  too, 
enlarged  glands  are  frequently  found  in  the  region  of  the  colic 
(iieo-caecal)  valve. 

The  nerves  of  the  small  intestine  are  derived  from  the 
aortic  sympathetic  plexus,  and  their  centres  in  the  spinal 
medulla  lie  in  the  ninth,  tenth,  and  eleventh  thoracic  segments. 
Referred  pain  in  connection  with  this  part  of  the  alimentary 
canal  is  felt  in  the  areas  supplied  by  the  ninth,  tenth,  and 
eleventh  thoracic  nerves  (Fig.  72),  and,  clinically,  it  usually 
involves  the  umbilical  region,  only  occasionally  spreading  to 
the  lumbar  region  and  the  back.  When  an  inguinal  hernia 
which  contains  small  intestine  becomes  strangulated,  the  pain 
is  at  first  experienced  near  the  umbilicus  and  not  immediately 
over  the  swelling. 

Structure  of  the  Small  Intestine. — Under  the  serous  (peritoneal) 
coat,  the  small  intestine  possesses  a  very  strong  muscular  coat.  This  consists 
of  an  outer  longitudinal  and  an  inner  circular  layer,  both  of  which  are  com- 
plete and  uninterrupted  from  the  pylorus  to  the  colic  (ileo-caecal)  valve. 
The  mucous  coat  is  thick,  and  it  is  thrown  into  ridges,  the  plicce  circulares 
(valvulce  conniventes),  which  begin  at  the  second  part  of  the  duodenum,  and 
are  most  numerous  in  its  third  and  fourth  parts  and  in  the  upper  part  of  the 
jejunum.  Lower  down  they  decrease  in  number,  and  they  are  entirely 
absent  in  the  lower  part  of  the  ileum.  In  this  situation  the  aggregated  lymph 
nodules  (Peyer's  patches),  which  are  not  present  in  the  jejunum,  are  fairly 
numerous  and  may  measure  4  x  \  inches.  They  form  somewhat  granular 
patches  in  the  mucous  coat,  and  lie  along  the  anti-mesenteric  border  of  the 
gut. 

Intestinal  Stasis. — Near  its  termination,  the  ileum  may 
become  kinked  and  obstructed  by  a  fibrous  band,  which  varies 
in  width  from  a  half  to  two  inches.  It  may  pass  downwards 
and  to  the  right  on  the  deep  surface  of  the  mesentery,  or  it  may 
ascend  from  the  pelvis  as  a  thickening  of  the  posterior  parietal 

21  b 


326  THE  ABDOMEN  AND   PELVIS 

peritoneum.  In  the  former  case,,  the  apex  of  the  kink  is  directed 
upwards,  and  the  proximal  and  distal  limbs  of  the  ileum, 
respectively,  ascend  and  descend  ;  in  the  latter  case,  the  condition 
is  exactly  reversed. 

It  is  generally  stated  that  these  bands  result  from  attacks 
of  appendicitis,  but  Lane  urges  that  those  which  hold  the  ileum 


FIG.  102.— Partial  Prolapse  of  the  Caecum.  The  Bismuth  is  also  visible  in 
the  Vermiform  Process,  which  passes  towards  the  left  and  then  turns 
downwards  into  the  pelvis.  The  vermiform  process  in  this  radiogram 
resembles  the  appearance  of  a  "Lane's  Kink,"  but,  at  the  subsequent 
operation,  it  was  found  in  the  position  shown  in  the  figure  and  with  the 
bismuth  still  in  situ. 

up  in  the  abdomen  are  produced  naturally  to  give  support  to  a 
prolapsing  caecum.  The  kinks  may  be  observed  in  radiograms 
taken  from  ten  to  twelve  hours  after  a  bismuth  meal.  The 
constricted  portion  of  the  terminal  part  of  the  ileum  is  recognised 
by  the  narrow  shadow  of  the  contained  bismuth,  while  the 
stronger  wide  shadows  represent  the  proximal  limb  of  the  kink 
and  the  caecum,  which  can  be  identified  by  its  characteristic 


THE  ABDOMINAL  CAVITY  327 

shape.  It  should  be  remembered  that  the  shadow  produced 
by  a  distended  vermiform  process,  which  is  constricted  near 
its  base,  may  be  misinterpreted  as  an  ileal  kink  (Fig.  102). 

The  condition  may  be  relieved  by  dividing  the  fibrous  band 
transversely,  but  Lane  contends  that  recurrence  is  certain  and 
that  ileo-pelvic-colostomy  is  necessary  (p.  345),  together  with 
the  removal  of  the  intervening  part  of  the  large  intestine.  Good 
results  follow  resection  of  the  caecum  and  the  terminal  part  of 
the  ileum,  with  an  end-to-side  anastomosis  between  the  ileum 
and  the  ascending  colon. 

Meckel's  Divertieulum. — In  the  early  human  embryo  the 
mid-gut  communicates  freely  with  the  yolk-sac  through  the 
vitello-intestinal  duct,  which  leaves  the  abdominal  cavity  at  the 
site  of  the  umbilicus  (Fig.  89).  As  the  embryo  develops,  the 
duct  becomes  occluded  and  later  entirely  disappears,  but  total 
or  partial  persistence  of  its  mtra-embryonic  portion  occurs  in 
about  two  per  cent  of  subjects.  It  is  then  known  as  a  Meckel's 
diverticulum,  and  the  condition  constitutes  the  commonest 
congenital  anomaly  of  the  small  intestine.  Many  varieties  are 
met  with,  from  a  complete  intestinal  diverticulum  opening  at 
the  umbilicus  to  a  small  elevation  on  the  wall  of  the  gut,  but 
the  diverticulum  always  springs  from  the  anti-mesenteric  border 
of  the  intestine  and  usually  within  three  or  four  feet  of  the  lower 
end  of  the  ileum. 

In  complete  persistence — congenital  umbilical  fistula — the 
duct  may  be  several  inches  in  length,  or  it  may  be  so  short  that 
the  ileum  itself  appears  to  open  on  the  surface  (Fig.  103,  i). 
In  the  latter  case  the  dorsal  or  mesenteric  wall  of  the  gut  may 
prolapse  through  the  opening,  giving  rise  to  a  turgid  swelling 
at  the  umbilicus  and  possibly  causing  intestinal  obstruction. 
This  condition  presents  an  appearance  very  similar  to  that 
produced  by  the  persistence  of  a  small  portion  of  the  extra- 
embryonic  part  of  the  vitello-intestinal  duct,  which  discharges 
mucus  and  is  not  necessarily  associated  with  a  Meckel's 
diverticulum  (Fig.  103,  iv).  The  passage  of  a  probe  at  once 
serves  to  indicate  which  of  the  two  varieties  is  present. 

In  partial  persistence  the  duct  is  represented  by  a  blind 
diverticulum  which  may  sometimes  be  attached  to  the  umbilicus 
by  a  fibrous  cord  (Fig.  103,  v).  The  free  diverticulum  is  the 
commonest  variety ;  it  is  subject  to  inflammatory  attacks 
and  may  form  adhesions  to  any  structure  in  its  neighbourhood, 
often  giving  rise  to  intestinal  obstruction.  As  the  centres  for 


328 


THE  ABDOMEN   AND   PELVIS 


the  diverticulum  and  the  vermiform  process  (appendix)  occupy 
the  same  segment  in  the  spinal  medulla,  the  reflex  sensory 
symptoms  are  very  similar,  and  consequently  inflammation  of 
the  diverticulum  may  easily  be  mistaken  for  appendicitis.  In 
the  cystic  variety  (Fig.  103,  v)  only  the  middle  part  of  the 
intra-embryonic  portion  of  the  duct  remains  patent. 

Differences  between  the  Large  and  Small  Intestine.— 
The  large  intestine  differs  from  the  small  intestine  in  its  outward 
appearance  in  several  particulars,  (i)  The  longitudinal  muscular 
coat  does  not  surround  the  large  intestine  completely.  Instead, 
it  forms  three  narrow  bands,  termed  the  tcenicz  coli,  which  are 
visible  through  the  serous  coat.  (2)  The  large  intestine  is 
sacculated.  (3)  Appendices  epiploicce  are  found  on  the  large 


I  II  III  IV  V 

FIG.  103. — Diagrams  to  illustrate  different  degrees  of  Persistence  of 

the  Vitello-intestinal  Duct. 

I,  II  and  III  show  different  stages  in  the  production  of  a  hernia  of  the  dorsal  wall  of 
the  small  intestine  through  a  patent  vitello-intestinal  duct  and  umbilicus. 

IV  shows  a  patch  of  granulations  at  the  umbilicus  and  a  partially  obliterated  vitello- 
intestinal  duct. 

V  shows  incomplete  obliteration  of  the  vitello-intestinal  duct  with  the  formation  of  a 
small  cyst  near  the  umbilicus. 

The  heavy  black  lines  represent  the  small  intestine,  and  the  shaded  area  represents 
the  anterior  abdominal  wall.     The  dotted  line  represents  the  peritoneum. 

intestine ;  they  consist  of  small  peritoneal  sacs  filled  with  fat. 
(4)  The  wall  of  the  large  intestine  is  thinner  than  the  wall  of  the 
small  intestine.  This  difference  is  referable  to  the  longitudinal 
muscular  and  the  mucous  coats. 

These  features  of  the  large  intestine  are  subject  to  a  good 
deal  of  variation. 

The  Colic  (Ileo-Caecal)  Valve  is  placed  at  the  junction  of 
the  ileum  with  the  large  intestine,  and  it  serves  to  demarcate 
the  caecum,  which  lies  below  it,  from  the  ascending  colon,  which 
lies  above  it.  The  position  of  the  valve  may  be  indicated  on 
the  surface  at  the  point  of  intersection  of  the  intertubercular 
and  the  right  lateral  planes. 


THE  ABDOMINAL  CAVITY  329 

The  valve  consists  of  an  upper  and  a  lower  segment,  which 
bound  a  horizontal  slit,  directed  forwards  and  to  the  right. 
The  segments  are  produced  by  an  invagination  of  the  mucous, 
submucous,  and  circular  muscular  coats  of  the  ileum  and 
caecum,  but  the  longitudinal  fibres  and  the  serous  coat  take  no 
part  in  their  formation.  Villi  are  found  on  the  ileal  surface  of 
the  valve,  but  the  mucous  membrane  of  its  caecal  surface  possesses 
the  characteristic  features  of  large  intestine.  Two  ridges,  which 
are  known  as  \hefrcenula,  pass  one  from  each  end  of  the  slit  and 
run  half-way  round  the  gut. 

The  colic  valve  is  arranged  so  as  to  prevent  the  regurgitation 
of  chyme  into  the  ileum,  while,  at  the  same  time,  it  offers  no 
hindrance  to  the  passage  from  the  ileum  into  the  caecum.  When 
the  caecum  is  loaded  the  fraenula  become  tightly  stretched,  and, 
as  a  result,  the  valve  is  securely  closed. 

The  Caecum  is  a  blind  sac  about  2\  inches  long  and  3  inches 
wide.  Normally  it  occupies  the  right  iliac  fossa,  and  is 
completely  invested  by  the  peritoneum,  so  that  it  can  be  lifted 
upwards  and  forwards  out  of  the  abdomen.  It  may  sometimes 
possess  a  mesentery,  or  it  may  not  be  covered  by  peritoneum 
posteriorly,  in  which  case  it  cannot  be  withdrawn  from  the 
abdomen  until  it  has  been  mobilised  (Fig.  104,  i).  Owing  to  the 
laxity  of  the  peritoneum,  the  normal  range  of  movement  may  be 
considerably  increased  in  some  cases  (mobile  ccecum),  and  this 
may  predispose  to  conditions  of  pericolitis,  with  symptoms 
closely  resembling  appendicitis. 

A  freely  movable  caecum  may  prolapse  into  the  pelvis  and 
become  distended  with  gas  and  fluid,  which  are  hindered  from 
escaping  by  the  pressure  of  the  pelvic  brim  and  the  superimposed 
coils  of  small  intestine.  As  it  enlarges,  the  over-distended 
caecum  drags  down  the  parietal  peritoneum,  giving  rise  to  painful 
symptoms.  When  the  gut  collapses,  on  the  escape  of  its 
contents,  the  loose  peritoneum  over  it  fails  to  return  to  its 
former  position  owing  to  lack  of  elasticity  and  becomes  wrinkled 
and  thrown  into  vascular  folds,  which  are  known  as  "  Jackson's 
veil."  This  condition  is  frequently  seen  in  the  region  of  the 
caecum  and  ascending  colon  during  operations  for  recurrent 
appendicitis.  Its  origin  has  been  variously  described  as 
congenital,  as  a  result  of  gradual  ptosis  of  the  caecum,  and  as 
inflammatory  following  chronic  pericolitis.  "  Jackson's  veil " 
is  very  commonly  seen  in  children  and  is  often  met  with  in  the 
adult,  but  it  is  rarely  to  be  observed  in  the  cadaver. 


330  THE  ABDOMEN  AND   PELVIS 

Inferiorly,  the  caecum  is  supported  by  the  lowest  part  of  the 
abdominal  wall,  and,  when  distended,  it  may  form  a  palpable, 
and  sometimes  visible,  tumour  in  this  region,  while  gurgling 
can  often  be  produced  by  manipulations.  Owing  to  its  proximity 
to  the  right  abdominal  inguinal  (internal  abdominal)  ring,  the 
caecum  and  vermiform  process  are  occasionally  found  in  a  right 
inguinal  hernia  in  children. 

In  structure  the  caecum  resembles  the  rest  of  the  large  intestine. 
The  longitudinal  muscular  coat  forms  three  distinct  bands  or 
taeniae.  Of  these  one  is  found  on  the  anterior  surface  of  the 
bowel,  a  second  on  the  posterior  surface,  while  the  third  is  placed 
on  the  medial  surface.  These  three  bands  converge  on  the 
base  of  the  vermiform  process,  which  they  provide  with  a 
complete  longitudinal  coat.  The  circular  muscular  coat,  as  in 
the  small  intestine,  is  uninterrupted,  and  the  mucous  coat 
contains  a  large  amount  of  lymphoid  tissue. 

Three  peritoneal  fossae  or  recesses  occur  near  the  termination 
of  the  ileum.  (i)  The  superior  ileo-ccecal  recess  (ileo-colic)  lies  in 
the  angle  between  the  ileum  and  the  ascending  colon.  The  an- 
terior caecal  artery  raises  a  fold  of  peritoneum  from  the  posterior 
abdominal  wall,  and  it  forms  the  anterior  boundary  of  the  recess. 
The  mouth  of  the  fossa  looks  downwards  and  to  the  left. 

(2)  The  inferior  ileo-ccecal  (ileo-appendicular)  recess  lies  in 
the  angle  between  the  ileum  and  the  caecum.     Its  anterior  wall 
is  formed  by  the  ileo-caecal  fold  (bloodless  fold  of  Treves),  and 
its  posterior  wall  is  usually  formed  by  the  mesentery  of  the 
vermiform  process.    The  ileo-caecal  fold  is  triangular  in  shape  ; 
its  apex  is  situated  at  the  ileo-caecal  junction  and  its  base  is  free, 
forming  the  anterior  boundary  of  the  mouth  of  the  fossa. 

(3)  The  cacal  (retro-c(ecal)  fossa  is  the  largest  and  most  con- 
stant of  the  fossae  in  this  region.     It  extends  upwards  behind  the 
caecum  as  far  as  the  line  of  peritoneal  reflection  from  that  viscus 
to  the  floor  of  the  iliac  fossa.     It  is  sometimes  limited  laterally 
by  a  fold  which  passes  downwards  and  laterally  across  the  lower 
part  of  the  right  para-colic  gutter  from  the  caeco-colic  junction. 

The  Vermiform  Process  (Appendix)  springs  from  the 
postero-medial  aspect  of  the  caecum  about  one  inch  below 
the  ileo-colic  junction,  and  can  always  be  found  by  tracing 
the  anterior  taenia  coli  downwards.  It  is  usually  about  3!  inches 
long  and  £  inch  wide,  but  its  length  is  very  variable,  being 
relatively  greater  in  the  child  than  it  is  in  the  adult.  The 
orifice  of  the  vermiform  process  communicates  with  the  caecum 


THE  ABDOMINAL  CAVITY  331 

and  is  guarded  by  a  crescentic  fold  of  mucous  membrane. 
Absence  or  incompetence  of  this  valve  may  account  for  the 
presence  of  faecal  matter  within  the  process. 

The  mesentery  of  the  vermiform  process  is  a  triangular  fold, 
which  is  derived  from  the  left  or  lower  layer  of  the  mesentery  of  the 
ileum.  It  is  sometimes  shortened  and  attached  to  the  posterior 
abdominal  wall  near  the  pelvic  brim.  Occasionally  the  vermiform 
process  has  no  mesentery  and  is  entirely  retro-peritoneal. 

Although  its  base  is  constant  in  position,  in  relation  to  the 
caecum,  the  process  itself  possesses  a  wide  range  of  movement 
and  may  occupy  any  one  of  the  following  situations  : 

(1)  It  may  pass  upwards  and  to  the  left,  under  cover  of  the 
mesentery  ;    this  is  known  as  the  splenic  position.    When  the 
process  is  retro-peritoneal  in  this  situation,  it  may  lie  behind 
or  within  the  root  of  the  enteric  mesentery. 

(2)  The  vermiform  process  may  pass  downwards  and  to  the 
left,  occupying  the  pelvic  position.     Inflammatory  attacks  may 
give  rise  to  adhesions  which  connect  it  to  the  rectum,  bladder, 
etc.     In  these  cases  defsecation  or  micturition  may  cause  painful 
symptoms  by  traction  on  the  adherent  vermiform  process,  and 
an  appendicular  abscess  may  discharge  by  the  rectum  or  the 
urethra.    When   the   vermiform   process   occupies   the   pelvic 
position  in  the  female,  it  is  brought  into  close  relationship  with 
the  right  ovary ;  and  if  signs  of  inflammation  occur,  it  may  be 
a  matter  of  great  difficulty  to  decide  whether  the  vermiform 
process  or  the  right  ovary  is  at  fault.    The  relation  of  the  pain 
to  the  menstrual  period  may  aid  in  the  diagnosis.     Valuable 
information  may  be  obtained  by  means  of  a  rectal  or  a  vaginal 
examination.     When  the  process  is  retro-peritoneal  in  the  pelvic 
position,  it  lies  immediately  in  front  of  the  common  iliac  vessels 
and  the  ureter,  and  difficulty  may  be  experienced  in  mobilising 
it  in  appendicectomy. 

(3)  The  vermiform  process  may  pass  forwards  towards  the 
anterior  abdominal  wall — the  anterior  position — but  it  can  only 
do  so  when  it  possesses  a  mesentery.     If  it  becomes  inflamed 
in  this  situation  the  greater  omentum  usually  surrounds    it, 
and  the  mass  so  formed  can  often  be  recognised  on  abdominal 
palpation.     Should  an  abscess  form  and  rupture,  the  right  infra- 
colic  compartment  may  be  infected  (p.  285). 

(4)  The    vermiform    process    very    frequently   takes    up    a 
position  behind  the  caecum  and  then  has  a  varying  relation  to 
the  peritoneum,     (a)  It  may  possess  a  mesentery  and  lie  free 


332 


THE  ABDOMEN  AND   PELVIS 


in  the  caecal  (retro-csecal)  fossa,     (b)  It  may  be  plastered  on  to 
the  posterior  aspect  of  the  caecum  by  the  peritoneum,  and  it 


FIG.  104. — Diagrams  to  illustrate  the  varying  relationships  of  the  Caecum, 
the  Vermiform  Process  and  the  Ascending  Colon  to  the  Peritoneum. 

1.  Absence  of  caecal  fossa  ;  posterior  wall  of  caecum  not  covered  by  peritoneum. 

2.  Normal  condition.     Caecal  fossa  present. 

3.  Csecal  fossa  extending  upwards  behind  ascending  colon.     Vermiform  process  retro- 
caecal  in  position  but  surrounded  by  peritoneum. 

4.  Vermiform  process  retro-caecal  in  position  but  enclosed  by  the  peritoneum  surround- 
ing the  caecum. 

5.  As  i  but  vermiform  process  is  entirely  extra-peritoneal. 

6.  Prolapse  of  caecum. 

7.  "  Undescended  caecum."     The  terminal  part  of  the  ileum,   as  it  ascends  to  the 
caecum,  is  retro-peritoneal.     The  vermiform  process  is  extra-peritoneal  except  at  its  tip, 
which  is  lying  in  front  of  the  kidney  in  the  posterior  wall  of  the  hepato-renal  recess. 
The  ascending  colon  and  the  right  colic  flexure  form  a  "double-barrelled  "  colon. 

8.  Ascending  colon  with  persisting  mesentery,  such  as  is  met  with  in  intussusception. 
Note. — The  dotted  line  represents  the  position  of  the  lumbo-sacral  articulation. 

then  lies  in  the  anterior  wall  of  the  fossa,     (c)  In  cases  where 
the  caecum  is  not  covered  by  peritoneum  posteriorly,,  the  retro- 


THE  ABDOMINAL  CAVITY  333 

csecal  vermiform  process  lies  in  contact  with  the  fascia  iliaca 
and  is  only  in  contact  with  peritoneum  at  its  base  (Fig.  104,  5.) 

The  course  taken  by  an  abscess  in  connection  with  a  retro- 
caecal  vermiform  process  will  depend  on  which  of  the  three 
varieties  is  present.  In  (a)  the  abscess  forms  in  the  lowest  part 
of  the  right  para-colic  gutter  and  reaches  the  anterior  abdominal 
wall  close  to  the  anterior  superior  iliac  spine.  It  then  gives 
rise  to  a  swelling,  which  is  dull  on  percussion.  Adhesions, 
however,,  may  shut  off  the  caeca!  fossa  so  that  the  abscess,  as 
it  enlarges,  pushes  the  caecum  forwards  with  the  result  that  a 
tympanitic  note  is  obtained  on  percussion  over  the  swelling. 

In  (b)  the  abscess  may  rupture  through  the  gut  wall  or  it  may 
burst  into  the  caecal  fossa,  in  which  event  the  condition  is  the 
same  as  that  described  for  (a). 

In  (c)  the  abscess  forms  in  the  extra-peritoneal  fat.  The 
caecum  is  thrust  forwards  against  the  anterior  abdominal  wall 
so  that  a  tympanitic  note  is  obtained  on  percussion,  and  this 
may  be  misleading,  unless  the  possibility  of  an  extra-peritoneal 
abscess  is  kept  in  mind.  Delay  in  recognising  this  condition 
allows  the  pus  to  spread  upwards  behind  the  peritoneum  until 
it  reaches  the  extra-peritoneal  subphrenic  danger  zone. 

Such  an  abscess  may  be  evacuated  by  the  extra-peritoneal 
route,  but  the  access  is  rarely  sufficient  for  removal  of  the 
vermiform  process,  and,  further,  a  wide  extent  of  cellular  tissue 
is  necessarily  opened  up.  It  is,  therefore,  better  to  empty  it 
through  the  peritoneal  cavity.  The  area  medial  to  the  ascending 
colon  and  caecum  is  packed  off,  and  the  floor  of  the  right  para-colic 
gutter  is  incised.  In  this  way  the  caecum  is  rendered  movable 
and  can  be  retracted  medially.  The  abscess  can  be  evacuated 
and  the  vermiform  process  removed  through  the  extended 
grid-iron  incision  (p.  248). 

(5)  The  infra-hepatic  position  is  referred  to  on  p.  346. 

The  ileo-colic  artery  arises  from  the  superior  mesenteric 
below  the  third  part  of  the  duodenum,  and  runs  downwards 
and  to  the  right  in  front  of  the  right  ureter  and  psoas  major 
(Fig.  1 06).  It  breaks  up  near  the  ileo-colic  fossa  into  branches 
which  supply  (i)  the  terminal  part  of  the  ileum,  (2)  the  ascending 
colon,  (3)  the  caecum,  and  (4)  the  vermiform  process.  The 
caecal  arteries,  anterior  and  posterior,  supply  the  anterior  and 
posterior  surfaces  of  the  caecum.  The  artery  to  the  vermiform 
process  descends  behind  the  ileum  and  enters  the  free  border 
of  the  mesentery  of  the  vermiform  process.  It  does  not 


334  THE  ABDOMEN  AND   PELVIS 

anastomose  with  any  other  artery,  and  therefore,  when  it 
becomes  kinked  or  obstructed,,  the  blood-supply  of  the  process 
is  entirely  cut  off  and  gangrene  ensues. 

Intussusception. — A  condition  of  incipient  intussusception 
is  always  present  on  account  of  the  invagination  of  the  circular 
muscular  coat  into  the  segments  of  the  colic  (ileo-csecal)  valve. 
This  constitutes  a  predisposition  to  ileo-ccecal  intussusception ,but 
the  condition  can  only  occur  when  the  ascending  colon  possesses 
a  mesentery.  The  frequency  of  its  incidence  during  the  first  year 
is  explained  by  the  fact  that  the  relative  disproportion  in  calibre 
between  the  large  and  small  intestine  is  greatest  at  that  period. 

It  is  said  that  if  a  wave  of  peristalsis  passes  up  the  caecum 
just  as  one  ends  on  the  ileum,  the  colic  valve,  which  is  at  that 
moment  projected  furthest  within  the  lumen  of  the  caecum,  is 
seized  by  the  contracting  caecum  and  squeezed  upwards  along 
the  ascending  colon.  When  the  angle  at  which  the  ileum  joins 
the  colon  is  greater  than  90°,  intussusception  occurs  more  readily. 

In  this  variety  the  colic  valve  forms  the  apex  of  the 
intussusceptum,  and  as  it  passes  along  the  large  intestine,  the 
caecum,  vermiform  process  and  ascending  colon  are  dragged  in 
together  with  the  ileum  and  its  mesentery.  Finally,  the  colic 
valve  may  appear  at  the  anus. 

In  the  ileo-colic  variety  the  intussusception  begins  in  the 
ileum,  usually  near  its  terminal  portion.  The  part  of  the  gut 
which  constitutes  the  starting-point  of  the  condition  remains 
at  the  apex  of  the  intussusceptum  (Fitzwilliams),  both  before 
and  after  it  has  passed  through  the  colic  valve.  If  the  ascending 
colon  possesses  a  mesentery,  the  subsequent  course  of  events  is 
the  same  as  in  the  ileo-caecal  variety.  If  the  ascending  colon 
has  no  mesentery,  the  intussusception  stops  at  the  valve. 

The  Ascending  Colon  runs  upwards  on  the  iliacus,  the 
quadratus  lumborum,  and  the  lower  pole  of  the  right  kidney 
(Fig.  88) ;  it  is  separated  from  both  muscles  by  their  fascia 
and  from  the  kidney  by  the  peri-nephric  fascia.  It  separates 
the  right  para-colic  gutter  from  the  right  infra-colic  compartment, 
and  is  bound  to  the  posterior  abdominal  wall  by  the  peritoneum, 
which  clothes  its  anterior,  medial,  and  lateral  surfaces. 
Occasionally  the  right  margin  of  the  greater  omentum  is  fused 
with  the  peritoneal  covering  of  the  ascending  colon.  In  that 
case  the  right  half  of  the  transverse  colon  is  often  closely  related 
to  the  ascending  colon,  forming  what  has  been  termed  the 
"  double-barrelled  gun  "  arrangement  (Fig.  105). 


THE  ABDOMINAL  CAVITY 


335 


The  Right  Colic  (Hepatic)  Flexure  lies  under  cover  of  the 
ninth  and  tenth  costal  cartilages  in  the  interval  between  the 
inferior  surface  of  the  right  lobe  of  the  liver  and  the  anterior 
surface  of  the  lower  pole  of  the  right  kidney.  It  is  formed  by 
the  terminal  part  of  the  ascending  colon,  which  turns  downwards, 
forwards,  and  to  the  left  to  become  continuous  with  the  transverse 
colon.  Its  medial  surface  is  in  contact  with  the  gall-bladder, 
anteriorly,  and  with  the  second  part  of  the  duodenum,  posteriorly. 


FIG.  105. — "Double-barrelled"  Colon.  The  dark  mass  on  the  left  of  the 
figure  consists  of  the  caecum,  the  ascending  colon  and  the  first  part  of 
the  transverse  colon. 

When  the  body  is  in  the  supine  position,  the  flexure  lies  a 
little  below  the  trans-pyloric  plane,  but  radiograms  show  that, 
in  the  erect  posture,  it  descends,  sometimes  even  to  the  level 
of  the  iliac  crest  (fourth  lumbar  vertebra).  The  amount  of 
peritoneum  which  persists  in  this  region  is  very  variable,  and 
this  fact  may  account  for  the  wide  range  of  movement. 

The  Transverse  Colon  extends  from  the  right  to  the 
left  colic  flexure.  As  it  crosses  the  abdominal  cavity  it  takes 
a  downward  curve,  usually  reaching  its  lowest  point  in  the 


336  THE  ABDOMEN  AND   PELVIS 

middle  line  where,  in  the  supine  position,  it  lies  at  or  a  little 
below  the  umbilicus.  In  many  cases,  however,  the  transverse 
colon  is  placed  at  a  much  lower  level,  and  its  position  depends 
on  (i)  its  length,  which  may  be  greatly  increased,  e.g.  in  cases 
of  undescended  caecum  (p.  346),  and  (2)  the  length  of  the 
transverse  meso-colon. 

In  the  erect  posture  the  transverse  colon  descends  still 
further,  and  is  often  seen  lying  behind  the  pubic  symphysis. 
Under  these  circumstances,  the  right  and  left  colic  flexures 
become  very  acute,  and  the  proximal  part  of  the  transverse 
colon  descends  in  front  of  or  medial  to  the  ascending  colon. 
If  these  two  pieces  of  bowel  are  attached  to  one  another 
by  peritoneal  bands  (p.  334)  or  adhesions,  the  kinking  will 
persist  in  the  supine  position  and  may  give  rise  to  delayed 
peristalsis  and  chronic  constipation. 

The  transverse  colon  is  completely  surrounded  by  peritoneum 
except  along  narrow  strips  on  its  upper  and  lower  surfaces, 
where  the  transverse  meso-colon  and  the  greater  omentum  reach 
the  gut  (Fig.  85). 

The  transverse  meso-colon  suspends  the  transverse  colon 
from  the  posterior  abdominal  wall.  It  is  attached  normally 
to  the  front  of  the  head,  neck,  and  body  of  the  pancreas,  but  it 
may  extend  further  over  to  the  right  and  cross  the  anterior 
surface  of  the  second  part  of  the  duodenum.  It  separates  the 
cavity  of  the  omental  bursa  from  the  infra-colic  compartments 
(Fig.  85),  and  is  related  to  the  stomach,  anteriorly,  and  to  the 
duodeno-jejunal  flexure  and  coils  of  small  intestine,  posteriorly. 
The  two  layers  of  the  transverse  meso-colon  contain  the  middle 
colic  vessels,  lymphatics,  and  nerves. 

The  BLOOD-SUPPLY  to  the  ascending  colon,  right  colic  flexure, 
and  the  transverse  colon  is  derived  from  (i)  the  right  and  (2) 
the  middle  colic  branches  of  the  superior  mesenteric  artery. 

(1)  The  right  colic  artery,  which  often  arises  by  a  common 
trunk  with  the  ileo-colic,  runs  to  the  right,  behind  the  peritoneum 
of  the  right  infra-colic  compartment.    It  crosses  in  front  of  the 
right  psoas  major,  ureter,  and  spermatic  vessels,  and  usually 
lies  a  little  below  the  right  kidney.    Near  the  gut  it  divides 
into  a  descending  branch,  which  anastomoses  with  the  colic 
branch   of   the   ileo-colic,   and   an   ascending   branch,   which 
anastomoses  with  the  right  division  of  the  middle  colic.    Both 
branches  supply  the  ascending  colon  (Fig.  106). 

(2)  The  middle  colic  arises  from  the  superior  mesenteric  at 


THE   ABDOMINAL  CAVITY 


337 


the  lower  border  of  the  pancreas  and  enters  the  root  of  the 
transverse  meso-colon.  Between  its  two  layers  the  artery 
passes  downwards  and  to  the  right  to  supply  the  transverse 


Para-colic  glands 


Middle  colic 
artery 


Right  colic 
artery 
Epi-colic  glands 

Intermediate 

glands 

Para-colic  glands 


Ileo-colic  artery  5 


Anterior  caecal 
artery 


Superior 
haemorrhoida 


Caecu 
Vermiform  process 

Appendicular  artery 

Slender  connection  between  lowest  sigmoid 
and  superior  haemorrhoidal  artery 

FIG.  1 06. — The  Arteries  and  Lymph  Glands  of  the  Large  Intestine. 

colon.  It  divides  into  a  right  branch,  which  supplies  the  right 
third  of  the  transverse  colon  and  anastomoses  with  the  ascending 
branch  of  the  right  colic  near  the  right  colic  flexure  ;  and  a  left 
branch,  which  supplies  the  left  two-thirds  of  the  transverse 
colon  and  anastomoses  with  the  ascending  branch  of  the  left 

22 


338  THE  ABDOMEN  AND   PELVIS 

colic  near  the  left  flexure  of  the  colon.  As  the  artery  lies 
somewhat  to  the  right  of  the  middle  line,  openings  in  the 
transverse  meso-colon  are  made  on  the  left  side  (p.  301). 

-  The  lymph  vessels  of  that  portion  of  the  large  intestine 
which  is  supplied  by  the  superior  mesenteric  artery  mainly 
follow  the  course  of  the  chief  blood-vessels.  The  lymph  glands 
are  divided  by  Jamieson  and  Dobson  into  four  groups,  (i) 
The  epi-colic  lymph  glands  are  situated  on  the  wall  of  the  gut. 
(2)  The  para-colic  lymph  glands  lie  on  the  medial  side  of  the 
ascending  colon  behind  the  posterior  parietal  peritoneum  ;  and 
above  the  transverse  colon,  between  the  two  layers  of  its 
mesentery.  (3)  The  intermediate  lymph  glands  are  associated 
with  the  ileo-colic,  right,  and  middle  colic  vessels.  (4)  The 
central  group  lies  along  the  superior  mesenteric  vessels  (Fig.  106). 

Efferents  pass  from  the  epi-colic  to  the  para-colic  lymph 
glands,  from  the  para-colic  to  the  intermediate  group,  and  from 
the  intermediate  to  the  central  group.  Some  efferents  from 
the  bowel  and  epi-colic  lymph  glands  pass  directly  to  the 
intermediate  group,  and,  on  this  account,  the  latter  must  be 
removed  together  with  the  bowel  and  the  para-colic  lymph 
glands  in  malignant  disease  (p.  339).  In  removing  retro- 
peritoneal  lymph  glands,  the  peritoneum  which  covers  them 
must  also  be  taken  away.  This  leaves  a  part  of  the  posterior 
abdominal  wall  bare,  and  the  surrounding  peritoneum  requires 
to  be  undermined  before  it  can  be  drawn  together  over  the 
denuded  area. 

Removal  of  Caecum  and  Ascending  Colon. — The  parts 
dealt  with  in  this  operation  are  more  or  less  fixed  in  position, 
and  their  blood  and  lymph  vessels  lie  behind  the  posterior 
parietal  peritoneum.  For  these  reasons  the  resection  of  the 
ascending  colon  presents  more  difficulty  than  the  removal  of 
a  part  of  the  small  intestine,  where  the  gut  is  freely  movable 
and  its  blood  and  lymph  vessels  are  easily  controlled  as  they 
lie  in  the  mesentery. 

The  extent  of  malignant  or  tuberculous  disease  in  the  ileo- 
csecal  region  may  be  so  limited  that  only  a  comparatively  small 
piece  of  the  gut  requires  to  be  removed.  If,  however,  the  right 
colic  (hepatic)  flexure  is  not  freely  movable,  some  difficulty  may 
be  experienced  in  approximating  the  two  cut  ends  in  the  subse- 
quent anastomosis.  Under  these  circumstances  it  is  advantageous 
to  remove  the  flexure  in  addition  to  the  diseased  area,  and  the 
more  movable  transverse  colon  can  then  be  united  to  the  ileum. 


THE  ABDOMINAL  CAVITY  339 

After  the  abdomen  has  been  opened  (p.  250),  the  surgeon 
(i)  may  first  ligature  the  ileo-colic  and  right  colic  arteries  and 
then  proceed  to  free  the  bowel ;  or  (2)  he  may  free  the  bowel 
first  and  secure  the  vessels  at  a  later  stage.  In  the  first  method 
the  vessels  are  found  behind  the  peritoneum  on  the  posterior 
wall  of  the  right  infra-colic  compartment  (Fig.  107). 

In  the  second  method  a  vertical  incision  is  made  through 
the  peritoneum  of  the  floor  of  the  right  para-colic  gutter  in  its 
whole  extent,  and  it  is  then  continued  to  the  left  behind  the 
caecum  and  below  the  ileum.  The  csecum  and  ascending  colon 
are  then  freed  by  dissecting  with  the  fingers,  and  the  peritoneum 
is  stripped  off  the  posterior  wall  of  the  right  infra-colic  com- 
partment. During  these  stages  of  the  operation  care  must 
be  taken  not  to  injure  the  right  spermatic  vessels,  ureter,  or  the 
second  part  of  the  duodenum  (Fig.  107).  The  contents  of  the 
right  iliac  fossa  can  now  be  drawn  out  of  the  abdomen  and 
turned  over  towards  the  left.  While  this  is  being  done,  the 
right  colic  and  ileo-colic  vessels  are  secured  on  the  deep  surface 
of  the  peritoneum.  The  ileum  and  ascending  (or  transverse) 
colon  are  then  clamped  and  divided,  and  the  intervening  portion 
of  bowel  is  removed,  together  with  the  adjoining  area  of 
peritoneum  up  to  the  point  where  the  arteries  have  been 
ligatured.  As  the  ileo-colic  artery  has  been  tied,  the  terminal 
six  inches  of  the  ileum  is  dependent  for  its  blood-supply  on 
the  anastomosis  between  the  ileo-colic  and  the  termination  of 
the  superior  mesenteric.  It  is  thus  rendered  unsuitable  for 
intestinal  anastomosis  and  must  be  resected  in  order  that  the 
piece  of  the  ileum  which  is  utilised  for  this  purpose  may  possess 
a  free  and  ample  blood-supply. 

The  Left  Colic  (Splenic)  Flexure  is  deeply  situated 
under  cover  of  the  costal  margin  and  is  partially  overlapped 
by  the  stomach.  On  this  account  its  examination  is  by  no 
means  easy,  and,  therefore,  tumours  of  the  flexure  are  not 
readily  recognised  at  an  early  stage.  Radiograms  demonstrate 
that  its  position  is  very  constant.  It  lies  under  cover  of  the 
eighth  rib  and  its  costal  cartilage,  to  the  left  side  of  the  left 
lateral  line,  and  it  is  held  in  place  by  its  peritoneal  connections. 
Its  upper  aspect  receives  the  attachment  of  the  upper  end  of 
the  left  border  of  the  greater  omentum ;  its  posterior  surface 
is  attached  to  the  pancreas  by  the  left  extremity  of  the  transverse 
mesocolon  ;  and,  from  its  lateral  aspect,  the  peritoneum  passes 
to  the  diaphragm  forming  a  fold,  which  is  called  the  phrenico- 

22  a 


340  THE  ABDOMEN  AND   PELVIS 

colic  ligament.  Superiorly,  the  flexure  is  in  contact  with  the 
lower  end  of  the  spleen,  and,  posteriorly,  it  rests  on  the  lateral 
part  of  the  anterior  surface  of  the  left  kidney. 

The  left  colic  artery,  which  is  a  branch  of  the  inferior 
mesenteric,  runs  upwards  and  to  the  left,  behind  the  peritoneum 
of  the  left  infra-colic  compartment  and  in  front  of  the  internal 
spermatic  vessels,  ureter,  and  kidney.  Before  it  reaches  the 
left  colic  flexure,  the  artery  divides  into  a  descending  branch, 
which  runs  downwards  along  the  medial  border  of  the  descending 
colon,  and  an  ascending  branch,  which  supplies  the  flexure  and 
then  enters  the  transverse  meso-colon  to  supply  the  transverse 
colon  and  anastomose  with  the  left  branch  of  the  middle  colic. 

The  lymph  vessels  of  the  left  flexure  pass  through  the  epi-  and 
para-colic  lymph  glands  to  reach  the  intermediate  group  on 
the  left  colic  artery.  Jamieson  and  Dobson  state  that  a  few 
lymph  vessels  from  the  flexure  enter  the  splenic  lymph  glands, 
and  that,  on  this  account,  complete  removal  of  the  lymphatic 
area  in  malignant  disease  of  the  flexure  is  impossible. 

Resection  of  the  left  colic  flexure  involves  the  removal 
of  the  left  third  of  the  transverse  colon  and  the  upper  part  of 
the  descending  colon.  This  necessitates  the  division  of  (i)  the 
peritoneum  in  the  left  para-colic  gutter,  (2)  the  phrenico-colic 
ligament,  (3)  the  left  part  of  the  greater  omentum,  and  (4)  the 
left  part  of  the  transverse  meso-colon.  In  this  way  the  flexure 
is  mobilised,  and  it  can  then  be  stripped  downwards  and  medially 
by  the  fingers.  During  this  process  care  must  be  exercised 
not  to  injure  the  kidney  or  ureter  (cf.  resection  of  right  flexure, 
p.  339).  The  ascending  branch  of  the  left  colic  artery  is  ligated 
on  the  posterior  surface  of  the  peritoneum,  and  the  left  branch 
of  the  middle  colic  is  caught  before  the  transverse  colon  and 
meso-colon  are  divided. 

The  Descending  Colon  is  about  four  inches  long  and 
extends  from  the  left  flexure  down  to  the  iliac  crest.  Above, 
it  lies  in  the  angle  between  the  left  kidney  and  the  transversus 
abdominis  ;  below,  it  lies  on  the  quadra tus  lumborum.  It 
separates  the  left  infra-colic  compartment  from  the  left  para-colic 
gutter,  and,  anteriorly,  it  is  in  relation  to  the  terminal  part  of 
the  transverse  colon  above,  and  to  coils  of  small  intestine  below. 
The  peritoneum  covers  the  descending  colon  in  front  and  on 
each  side,  but  this  part  of  the  gut  rarely  possesses  a  mesentery. 
The  descending  colon  is  in  direct  contact  with  the  extra-peritoneal 
fat  (p.  275). 


THE   ABDOMINAL  CAVITY  341 

The  Iliac  Colon  descends  on  the  iliacus  muscle  to  the 
level  of  the  antero-superior  iliac  spine  and  then  turns  medially, 
parallel  to,  and  a  little  above,,  the  inguinal  ligament.  It  forms 
the  medial  boundary  of  the  left  paracolic  gutter  and  ends,  at 
the  brim  of  the  pelvis,  by  becoming  continuous  with  the  pelvic 
colon.  Like  the  descending  colon,  the  iliac  colon  is  retro- 
peritoneal  and  rarely  possesses  a  mesentery.  Tumours  of  the 
iliac  colon  are  not  difficult  to  recognise,  as  they  may  be  palpated 
by  rolling  the  gut  against  the  ilium.  Scybalous  masses  may  be 
distinguished  by  the  fact  that  they  can  be  pitted  on  firm  pressure. 

The  Pelvic  Colon,  which  varies  from  ten  to  thirty  inches 
in  length,  is  continuous  with  the  iliac  colon  above  and  terminates 
in  front  of  the  third  piece  of  the  sacrum,  where  it  becomes 
continuous  with  the  rectum.  It  is  suspended  from  the  posterior 
wall  of  the  pelvis  by  a  mesentery,  termed  the  pelvic  meso-colon, 
and  consequently  is  freely  movable.  The  line  of  attachment 
of  its  mesentery  resembles  an  inverted  V.  It  begins  on  the 
medial  border  of  the  psoas  major  and  passes  upwards  and 
medially  along  the  medial  side  of  the  external  iliac  vessels. 
After  crossing  the  hypogastric  (internal  iliac)  artery,  it  bends 
sharply  downwards  and  ends  in  front  of  the  third  sacral  vertebra. 
On  account  of  the  arrangement  of  the  mesentery,  the  terms 
ascending  and  descending  limbs  are  used  with  reference  to  the 
pelvic  meso-colon  and  to  the  parts  of  the  gut  which  they  enclose. 

A  small  intra- peritoneal  fossa,  termed  the  inter sigmoid 
recess,  lies  at  the  apex  of  the  inverted  V  and  is  bounded  on  each 
side  by  the  left  or  lower  layer  of  the  pelvic  meso-colon.  This 
recess  is  sometimes  the  site  of  an  intra-peritoneal  strangulated 
hernia. 

The  pelvic  colon  is  usually  situated  partly  in  the  pelvis  and 
partly  in  the  abdomen.  When  it  possesses  a  long  mesentery,  it 
may  pass  across  the  median  plane,  and  it  is  not  infrequently 
seen  during  the  operation  of  appendicectomy.  In  the  child  it 
lies  mainly  in  the  abdomen,  owing  to  the  relatively  small  size 
of  the  pelvic  cavity. 

The  advantage  taken  by  the  surgeon  of  a  freely  movable 
pelvic  colon  is  pointed  out  on  p.  343. 

The  Inferior  Mesenteric  Artery  arises  from  the  abdominal 
aorta  ij  inches  above  its  bifurcation.  It  runs  downwards 
and  slightly  to  the  left,  and  gives  off  the  left  colic  (p.  340) 
and  the  sigmoid  arteries.  Its  downward  continuation  into  the 
pelvis  is  called  the  superior  hcemorrhoidal  artery. 

22  b 


342 


THE  ABDOMEN  AND   PELVIS 


The  sigmoid  arteries,  three  or  four  in  number,  supply  the 
iliac  and  pelvic  cola.     They  anastomose  freely  with  one  another, 


Superior 
mesenteric 
artery 
Right  para- 
colic  gutter 
Right  and 
middle  colic 


Lower 
of  left 
kidney 


FIG.  107. — The  Posterior  Wall  of  the  Infra-colic  Compartment.  The  greater 
omentum  and  the  transverse  colon  have  been  thrown  upwards.  The 
mesentery  has  been  divided  close  to  its  root  and  removed  together  with 
the  coils  of  the  jejunum  and  ileum.  A  small  part  of  the  pelvic  colon 
and  its  mesentery  has  been  resected  to  expose  the  pelvic  portion  of  the 
left  ureter. 

forming  arterial  arcades  across  the  iliac  fossa  and  in  the  pelvic 
meso-colon.  The  highest  of  the  series  similarly  anastomoses 
with  the  descending  branch  of  the  left  colic.  The  anastomosis 
between  the  lowest  sigmoid  and  the  superior  haemorrhoidal  is 


THE  ABDOMINAL  CAVITY  343 

not  always  sufficient  to  re-establish  the  circulation,  if  the  inferior 
mesenteric  artery  is  ligatured  beyond  the  origin  of  the  lowest 
sigmoid  branch.  In  abdomino-perineal  or  abdomino- sacral 
removal  of  the  rectum,  the  inferior  mesenteric  requires  to  be 
ligated.  If  the  ligature  is  applied  below  the  origin  of  the  lowest 
sigmoid  artery,  the  vitality  of  the  lower  part  of  the  pelvic  colon 
is  seriously  imperilled.  It  is  necessary,  therefore,  to  apply  the 
ligature  on  the  proximal  side  of  the  lowest  sigmoid  branch. 
The  anastomosis  between  the  sigmoids  is  sufficient  to  ensure 
the  passage  of  blood  through  the  lowest  sigmoid  back  into  the 
inferior  mesenteric,  and  thus  the  blood-stream  reaches  the  pelvic 
colon  along  the  normal  channel. 

Colotomy. — The  pelvic  colon  is  usually  selected  as  the  site 
for  an  inguinal  colotomy  on  account  of  its  wide  range  of 
movement.  A  loop  of  the  gut  with  its  mesentery  is  brought 
out  of  the  abdomen  through  the  left  rectus  and  its  sheath,  or 
through  a  gridiron  incision  which  is  made  at  a  slightly  lower 
level  than  the  appendicular  incision  (p.  248)  on  the  opposite 
side.  A  glass  rod  or  rubber  tube  is  passed  through  the  mesentery 
to  support  the  bowel  by  resting  on  the  skin  surface  on  each  side 
of  the  wound,  and  the  serous  and  muscular  coats  of  the  colon 
are  stitched  to  the  parietal  peritoneum. 

Owing  to  the  circular  course  followed  by  the  blood-vessels 
in  the  wall  of  the  gut,  the  colotomy  opening  is  made  transversely. 
If  complete  division  of  the  bowel  and  its  mesentery  is  carried 
out,  only  one  or  two  small  vessels  in  the  edge  of  the  pelvic 
meso-colon  require  to  be  tied.  This  part  of  the  operation  is 
quite  painless  and  may  be  carried  out  without  any  anaesthetic. 

Many  surgeons  prefer  to  make  the  opening  near  the  com- 
mencement of  the  pelvic  colon,  because  when  a  more  distal 
portion  is  used  there  is  subsequently  a  distinct  tendency  to 
prolapse  of  the  mucous  membrane.  On  the  other  hand,  when 
the  opening  is  made  in  the  lower  part  of  the  pelvic  colon,  the 
proximal  loop  of  the  pelvic  colon  acts  as  a  reservoir. 

In  some  cases  the  pelvic  colon  and  meso-colon  are  so  short 
that  it  is  impossible  to  bring  the  bowel  out  at  the  abdominal 
wound.  It  is  then  necessary  either  to  mobilise  the  iliac  colon 
by  dividing  the  peritoneum  freely  along  the  left  paracolic  gutter, 
or  to  utilise  the  transverse  colon  or  the  caecum. 

The  Excision  of  a  part  of  the  pelvic  colon  presents  little 
difficulty  when  the  gut  possesses  a  long  mesentery,  and  axial 
anastomosis  may  be  carried  out.  When  the  pelvic  meso-colon 

'2'2  c 


344  THE  ABDOMEN  AND  PELVIS 

is  short  it  may  be  necessary  to  mobilise  the  lowest  portion  of 
the  iliac  colon.  This  can  be  effected  by  dividing  the  peritoneum 
along  the  left  paracolic  gutter  and  stripping  the  bowel  medially 
on  a  hinge  of  peritoneum.  The  lateral  cutaneous  nerve  of  the 
thigh;  the  ductus  deferens,  the  internal  spermatic  vessels,  and 
the  genito-femoral  nerve  may  be  injured  unless  care  is  exercised 
at  this  stage  of  the  operation.  In  addition,  the  ureter,  which  is 
crossed  by  the  root  of  the  pelvic  meso-colon  near  the  apex  of 
the  V,  and  the  inferior  mesenteric  artery  and  its  terminal  branch 
which  runs  downwards  in  the  descending  limb  of  the  pelvic 
meso-colon  (Fig.  107),  must  all  be  preserved. 

Transplantation  of  Ureters. — The  mobility  of  the  pelvic 
colon  renders  it  suitable  for  the  implantation  of  the  divided 
ureters  in  cases  of  extroversion  of  the  bladder  and  in  epi- 
spadias  (in  both  sexes)  with  associated  incontinence  of  urine 
(Stiles).  It  might  be  supposed  that  the  introduction  of  the 
ureters  into  a  septic  tube  would  lead  to  an  ascending  infection 
of  the  urinary  tract,  but  provided  that  the  urine,  ureters,  and 
kidneys  are  healthy  there  is  no  risk  of  such  an  occurrence. 
After  the  operation  the  bowels  may  be  unnaturally  loose  for 
a  time,  but  the  rectum  rapidly  becomes  tolerant  of  the  presence 
of  the  urine  so  that  the  bowels  act  only  once  or  twice  a  day. 

The  operation  of  transplantation  is  performed  in  two  stages, 
an  interval  of  a  fortnight  being  allowed  to  elapse  before  the 
second  ureter  is  transplanted. 

Very  careful  preparation  of  the  patient  on  each  occasion  is 
essential  to  ensure  an  empty  pelvic  colon. 

The  patient  is  placed  in  an  exaggerated  Trendelenburg 
position  in  order  to  facilitate  the  exposure  of  the  ureters.  A 
vertical  incision  through  the  left  rectus  gives  good  access,  due 
care  being  taken  to  ligate  the  inferior  epigastric  artery.  In 
the  case  of  the  left  ureter,  the  coils  of  small  intestine  are  displaced 
upwards,  and  the  pelvic  colon  is  identified.  It  is  then  turned 
upwards,  and  the  peritoneum  in  the  floor  of  the  intersigmoid 
fossa  (Fig.  107)  is  carefully  divided.  The  pelvic  portion  of 
the  ureter  is  now  exposed  and  may  be  traced  downwards  and 
freed  before  it  is  ligated  and  divided.  Its  extremity  is  then 
implanted  into  the  ascending  limb  of  the  gut,  and  the  adjacent 
part  of  it  is  buried  in  the  wall  of  the  bowel  after  the  manner 
adopted  in  Witzel's  gastrostomy.  The  peritoneal  and  abdominal 
incisions  are  then  closed. 

The  right  ureter  is  found  near  the  medial  border  of  the  right 


THE  ABDOMINAL  CAVITY  345 

psoas  major,  after  it  has  been  crossed  by  the  root  of  the  mesentery 
(Fig.  107).  The  peritoneum  over  it  is  carefully  incised,  and  it 
is  then  traced  downwards  and  divided.  The  cut  end  is  then 
approximated  to  the  descending  limb  of  the  pelvic  colon,  and 
the  implantation  is  carried  out  as  before. 

In  Ileo-Pelvic-Colostomy  an  anastomosis  is  established 
between  the  terminal  part  of  the  ileum  and  the  pelvic  colon. 
The  operation  is  performed  in  chronic  intestinal  stasis,  or  for 
threatened  obstruction  in  the  intervening  parts  of  the  large 
bowel.  It  is  carried  out  with  the  pelvis  slightly  elevated,  and 
good  access  is  obtained  by  a  median  infra-umbilical  incision. 

Care  must  be  taken  to  divide  the  ileum  on  the  proximal  side 
of  any  obstructing  bands  (p.  325),  and  in  such  a  way  that  it 
can  be  connected  to  the  pelvic  colon  without  any  subsequent 
tension  on  the  anastomosis.  After  the  ileum  has  been  cut 
through,  the  mesentery  is  divided  very  slightly  to  facilitate  the 
invagination  of  the  distal  cut  end  of  the  gut.  In  bringing  the 
ileum  into  apposition  with  the  pelvic  colon,  its  cut  end  must  be 
rotated  counter-clockwise  in  order  that  the  left  or  lower  surface 
of  the  mesentery  may  lie  in  contact  with  the  right  surface  of  the 
descending  limb  of  the  pelvic  meso-colon.  If  the  cut  end  is 
rotated  in  the  opposite  direction,  the  enteric  mesentery  is 
twisted  and  the  ileum  may  subsequently  become  kinked.  The 
anastomosis  between  the  cut  end  of  the  ileum  and  the  side  of 
the  descending  limb  of  the  pelvic  colon  is  then  completed.  As 
a  result  the  anastomosis  forms  a  bridge  in  front  of  a  patent 
passage  between  the  mesentery  and  the  pelvic  meso-colon,  and 
in  order  to  prevent  the  occurrence  of  an  intra  -  peritoneal 
strangulated  hernia  the  two  mesenteries  are  closely  drawn 
together  by  means  of  a  linen-thread  purse-string  suture. 

Development  of  the  Intestines. — The  alimentary  canal  caudal  to  the 
stomach  elongates  much  more  rapidly  than  the  posterior  abdominal  wall, 
and  the  growth  of  the  mesentery  keeps  pace  with  it.  A  U-shaped  loop  is 
thus  formed,  which  passes  out  of  the  abdomen  through  the  patent  umbilicus 
(p.  288),  carrying  down  the  superior  mesenteric  artery  between  the  two  layers 
of  the  mesentery.  An  evagination  appears  on  the  distal  limb  of  the  U  and 
subsequently  forms  the  caecum  and  the  vermiform  process.  Shortly  after 
its  appearance  the  gut  becomes  rotated  round  the  superior  mesenteric  artery, 
so  that  the  distal  limb  of  the  loop  is  carried  across  the  ventral  surface  of  the 
proximal  limb  (Fig.  90).  When  the  loop  is  withdrawn  into  the  abdomen  again 
(p.  288)  it  is  found  that,  as  a  result  of  this  rotation,  the  transverse  colon 
crosses  in  front  of  the  duodenum. 

Thereafter,  the  mesentery  of  the  large  intestine  partially  disappears  and 
only  persists  for  the  transverse  and  pelvic  cola.  After  the  rotation  the 
transverse  colon  lies  behind  the  greater  omentum  (p.  303),  and  its  mesentery 


346  THE  ABDOMEN  AND  PELVIS 

blends  with  the  two  posterior  layers  of  the  latter  so  that  this  part  of  the  gut 
attains  the  peritoneal  relationship  which  is  found  in  the  adult. 

The  caecal  outgrowth  rapidly  increases  in  length.  Its  proximal  fourth 
or  less  forms  the  caecum,  and  its  distal  part  forms  the  vermiform  process. 
At  birth  the  caecum  is  conical  in  shape  and  the  vermiform  process  is  attached 
to  its  apex.  This  condition  may  persist — the  infantile  ccecum — but,  normally, 
the  lateral  wall  of  the  caecum  increases  more  rapidly  than  the  medial  wall, 
and  in  the  adult  the  vermiform  process  springs  from  the  latter.  After  the 
viscera  are  withdrawn  from  the  umbilical  cord  (p.  288)  into  the  abdomen, 
the  caecum  lies  in  relation  to  the  under  surface  of  the  liver  in  continuity  with 
the  transverse  colon.  As  the  colon  increases  in  length,  the  caecum  gradually 
descends,  and  at  birth  it  lies  in  the  right  iliac  fossa.  Mai-descent  or  non- 
descent  is  a  well-recognised  anomaly  and  the  caecum  is  then  frequently  of  the 
infantile  type.  When  it  is  not  found  in  its  normal  position  in  abdominal 
operations  the  possibility  of  this  condition  must  be  borne  in  mind. 

Prior  to  the  descent  of  the  caecum  the  vermiform  process  may  take  up 
a  retro-caecal  position,  and  it  may  become  fixed  in  this  situation,  losing  its 
peritoneal  covering.  When  the  caecum  descends  the  vermiform  process  is 
left  behind  in  the  extra-peritoneal  retro-caecal  position  (Fig.  104,  7). 

Sometimes  the  rotation  of  the  intestines  is  excessive,  so  that  the  caecum 
is  carried  across  the  duodenum  to  its  left  side.  It  will  then  be  found,  together 
with  the  vermiform  process,  between  the  two  layers  of  the  transverse  meso- 
colon,  while  the  terminal  part  of  the  ileum  occupies  the  areas  in  which  the 
caecum,  ascending  colon,  and  right  colic  flexure  are  normally  found. 

The  mesenteries  of  the  ascending,  descending,  and  iliac  cola  often  persist 
during  childhood  and  disappear  later.  This  accounts  for  the  incidence  of 
intussusception,  in  which  the  whole  length  of  the  large  intestine  commonly 
possesses  a  mesentery.  More  rarely,  an  excess  of  peritoneum  may  persist 
in  the  adult,  and  such  a  persistence  may  explain  the  condition  of  "  mobile 
caecum  "  and  the  accompanying  "  Jackson's  veil  "  (p.  329). 

The  Kidneys  lie,  one  on  each  side  of  the  vertebral  column, 
opposite  the  twelfth  thoracic,  first,  second,  and  third  lumbar 
vertebrae,  but  owing  to  the  large  size  of  the  right  lobe  of  the 
liver  the  right  one  usually  lies  at  a  somewhat  lower  level  than 
the  left.  The  kidney  is  about  2  inches  wide  and  4!  inches  long; 
and  its  long  axis  is  directed  from  above  downwards  and  laterally. 
The  upper  pole  is  limited  above  by  a  horizontal  plane  drawn  mid- 
way between  the  transpyloric  plane  and  the  xiphisternal  junction; 
the  lower  pole  extends  to  the  subcostal  plane.  The  transpyloric 
plane  passes  through  the  hila  of  both  kidneys  at  about  i  \  inches 
from  the  median  plane.  When  the  position  of  the  hilum  is 
determined  on  the  surface  it  is  not  difficult  to  map  out  the 
kidney  with  the  help  of  the  facts  which  have  been  enumerated. 

The  Ureters  may  be  indicated  on  the  anterior  abdominal 
wall  by  lines  drawn  downwards  from  each  hilum  at  a  distance 
of  i£  inches  from  the  median  plane.  These  vertical  lines 
trisect  the  line  joining  the  anterior-superior  iliac  spines  at  points 
which  correspond  to  the  bifurcations  of  the  common  iliac  arteries. 
These  vertical  lines  correspond  to  the  abdominal  parts  of  the 


THE  ABDOMINAL  CAVITY  347 

ureters  and  pass  through  the  tips  of  the  lumbar  transverse 
processes.  The  pelvic  part  of  the  ureter  may  be  indicated  by 
a  line  which  curves  downwards  and  medially,  with  a  slight 


L. 

FIG.  108. — Small  Calculus  impacted  in  the  Right  Ureter.  The  radiogram 
was  taken  a  few  days  after  an  attack  of  right  renal  colic.  The  outline 
of  the  lower  pole  of  the  kidney  is  faintly  visible.  (Bythell  and  Barclay's 
X-ray  Diagnosis  and  Treatment. ) 

downward  convexity,  from  the  iliac  bifurcation  to  the  pubic 
tubercle  (spine). 

Posteriorly,  the  transpyloric  plane  passes  through  the  lower 
border  of  the  first  lumbar  spine.     The  hilum  of  the  kidney  lies 


348  THE  ABDOMEN  AND   PELVIS 

1 1  inches  lateral  to  the  spine  of  the  first  lumbar  vertebra,  and 
the  whole  kidney  can  be  mapped  out  on  the  dorsal  surface  of 
the  body  from  the  measurements  already  given. 


FIG.  109. — Calcareous  Lymph  Gland,  between  the  Transverse  Processes  of 
the  Fourth  and  Fifth  Lumbar  Vertebrae.  The  sacro-iliac  joint  is 
well  shown. 

The  abdominal  part  of  the  ureter  corresponds  to  a  line 
drawn  from  the  hilum  to  the  postero  -  inferior  iliac  spine 
(Fig.  84). 

A  knowledge  of  the  topography  of  the  kidneys  and  ureters 
is  essential  for  the  correct  interpretation  of  radiograms,  in 


THE  ABDOMINAL  CAVITY  349 

which  the  question  arises  as  to  whether  a  certain  shadow  may 
or  may  not  be  produced  by  a  calculus. 

The  shadows  thrown  by  phleboliths  or  calcareous  deposits 
in  the  mesenteric  or  iliac  lymph  glands  may  be  difficult  to 
distinguish  from  shadows  caused  by  ureteral  calculi  (Figs.  108 
and  109).  Phleboliths,  however,  are  much  more  commonly 
found  in  the  vesico-prostatic  veins  (p.  365),  but  even  in  this 
position  they  may  throw  shadows  in  relation  to  the  vesical 
openings  of  the  ureters. 

Although  the  normal  line  of  the  ureter  passes  through  the 
tips  of  the  lumbar  transverse  processes,  shadows  found  more 
medially  may  nevertheless  be  due  to  ureteral  calculi,  because 
when  hypertrophied  as  the  result  of  urinary  obstruction,  the 
ureter  takes  an  irregular  downward  course. 

The  peri-nephric  fascia  and  the  posterior  relations  of  the 
kidneys  have  already  been  described  (p.  271). 

The  Right  Kidney  is  in  contact,  anteriorly,  with  the 
suprarenal  gland,  the  liver,  the  right  colic  flexure,  and  the 
duodenum.  The  suprarenal  gland  lies  on  its  upper  pole,  and 
below  that,  the  liver  covers  nearly  two-thirds  of  its  anterior 
surface.  The  second  part  of  the  duodenum  lies  along  the  medial 
border  overlapping  the  hilum,  and  the  right  colic  flexure  covers 
the  infero-lateral  part  of  this  surface.  Over  the  hepatic  area 
the  peritoneum  is  in  direct  contact  with  the  kidney,  forming 
the  posterior  wall  of  the  hepato-renal  recess  (p.  282) ;  elsewhere 
it  is  lifted  off  by  the  related  viscera. 

Excision  of  the  Right  Kidney  may  require  to  be  performed 
from  the  front,  when  the  viscus  is  too  large  to  be  removed 
through  the  loin.  A  long  vertical  incision  is  made  through 
the  anterior  abdominal  wall,  commencing  above  at  the  tenth 
costal  cartilage.  Owing  to  the  length  of  the  wound,  the  ninth, 
tenth,  and  eleventh  intercostal  nerves  have  to  be  sacrificed  as 
free  access  is  essential.  The  abdominal  cavity  having  been 
opened,  the  peritoneum  is  incised  along  the  upper  part  of  the 
right  paracolic  gutter  and  the  hepato-renal  recess.  It  is  carefully 
stripped  off  the  hepatic  area,  and  the  ascending  colon,  right 
colic  flexure,  second  part  of  the  duodenum,  and  the  head  of  the 
pancreas  are  turned  medially.  In  this  way  the  anterior  surface 
of  the  kidney  is  exposed,  and  the  pedicle  formed  by  the  renal 
artery  and  vein  can  be  defined  by  careful  blunt  dissection. 
The  vein  is  the  most  anterior  structure  at  the  hilum  and  the 
ureter  and  its  dilated  pelvis  the  most  posterior,  while  the  artery 


350  THE  ABDOMEN  AND  PELVIS 

occupies  an  intermediate  position.  The  ureter  is  ligated  in  two 
places  and  divided.  Next  a  ligature  is  passed  round  the  vascular 
pedicle  and  the  artery  and  vein  may  then  be  ligated  separately 
nearer  to  the  kidney.  The  viscus  is  removed,  after  it  has  been 
separated  from  the  surrounding  peri-nephric  fat. 

In  advanced  tuberculous  disease  and  hydronephrosis  the 
vascular  supply  may  be  much  diminished,  and  it  may  be  im- 
possible to  define  the  vascular  pedicle  owing  to  the  presence 
of  adhesions.  Care  must  be  exercised  in  these  cases  not  to  exert 
traction  on  the  kidney,  because  the  right  renal  vein,  which  is  a 
short  vessel,  may  tear  away  from  the  inferior  vena  cava.  This 
risk  can  sometimes  be  avoided  by  splitting  the  capsule  and 
shelling  out  the  kidney  from  inside.  The  bleeding  vessels  can 
be  secured  as  they  are  encountered,  and  subsequently  portions 
of  the  capsule  can  be  cut  away. 

The  Left  Kidney  is  crossed  at  about  the  middle  of  its 
anterior  surface  by  the  pancreas  and  splenic  vessels  (Fig.  87). 
Above  the  pancreas,  the  left  kidney  is  related  to  the  spleen, 
laterally,  and  to  the  suprarenal  gland,  medially.  The  area 
between  these  two  viscera  lies  in  the  posterior  wall  of  the 
omental  bursa  and  forms  a  part  of  the  stomach  bed.  Below  the 
pancreas,  the  first  coil  of  the  jejunum  covers  the  whole  surface 
except  a  strip  along  the  lateral  border,  which  is  in  contact  with 
the  left  colic  flexure  and  the  descending  colon. 

The  peritoneum  is  lifted  off  the  kidney  by  the  descending 
colon,  the  pancreas,  and  the  suprarenal  gland,  which  are  all  in 
direct  contact  with  the  viscus.  The  lieno- renal  ligament 
reaches  the  kidney  above  the  pancreas,  and  its  right  layer  is 
continued  over  the  gastric  area,  while  its  left  layer  covers  the 
area  in  contact  with  the  spleen  (Fig.  87).  The  area  related 
to  the  jejunum  is  covered  by  the  downward  continuation  of  the 
lower  layer  of  the  transverse  meso-colon. 

It  should  be  noted  that  the  left  kidney  is  found  in  three 
regions,  viz.  (i)  the  omental  bursa,  (2)  the  left  infra-colic 
compartment,  and  (3)  the  lieno-renal  recess,  at  the  upper  end 
of  the  left  paracolic  gutter. 

Excision  of  the  Left  Kidney  is  carried  out  by  a  method 
very  similar  to  that  adopted  for  the  right  kidney.  After  the 
abdominal  cavity  has  been  opened,  the  peritoneum  in  the  upper 
part  of  the  left  paracolic  gutter,  the  phrenico-colic  ligament, 
and  the  peritoneum  along  the  upper  part  of  the  lateral  border 
of  the  kidney  are  all  incised.  The  descending  colon  and  left 


THE  ABDOMINAL  CAVITY  351 

colic  flexure  are  then  stripped  medially  and  the  whole  of  the 
anterior  surface  of  the  kidney  can  be  exposed. 

The  peritoneum  must  not  be  incised  along  the  medial  border 
of  the  bowel  lest  the  colic  vessels  be  injured.  Further,  in  the 
excision  of  either  kidney,  the  possible  presence,  generally  at  the 
lower  pole,  of  one  or  more  supernumerary  renal  arteries  must  be 
remembered. 

The  trans-peritoneal  operation  for  excision  of  the  kidney 
possesses  one  great  advantage  over  the  lumbar  or  extra-peritoneal 
operation,  namely,  that  the  surgeon  is  able  to  palpate  both 
kidneys  through  the  incision  in  the  abdominal  wall. 

Structure  of  the  Kidney, — The  hilum  of  the  kidney  leads  into  a  space, 
termed  the  renal  sinus,  into  the  cavity  of  which  numerous  renal  papillae 
project.  On  section,  the  kidney  is  seen  to  possess  a  narrow  cortical  and  a 
deeper  medullary  layer.  The  latter  is  darker  in  colour  and  striated  in  appear- 
ance, and  is  subdivided  into  a  number  of  small  pyramids,  the  apices  of  which 
constitute  the  renal  papillae. 

At  the  hilum  the  ureter  becomes  greatly  dilated  to  form  the  renal  pelvis 
(pelvis  of  ureter),  which  divides  into  two  or  sometimes  three  calyces  majores. 
Each  calyx  major  subdivides  into  smaller  calyces,  and  each  of  the  latter  is 
associated  with  one  or  more  renal  papillae,  receiving  the  urine  from  the 
uriniferous  tubules  which  open  on  their  surfaces. 

Calculi  may  form  in  the  kidney,  calyces,  or  renal  pelvis, 
and  give  rise  to  hydronephrotic  changes  by  obstructing  the 
urinary  outflow  ;  on  the  other  hand,  a  stone  may  lie  latent  for 
a  considerable  period. 

A  stone  or  stones  lying  in  the  renal  pelvis  may  be  removed 
by  incising  the  pelvis  and  without  cutting  into  the  kidney. 
This  is  best  carried  out  by  the  lumbar  route,  and  after  the  kidney 
has  been  brought  to  the  surface,  it  is  turned  slightly  forwards 
and  the  pelvis  is  incised  horizontally.  Occasionally  one  or 
more  of  the  renal  vessels  may  intervene,  but  these  may  be 
retracted  out  of  the  way.  The  pelvis  heals  extremely  readily, 
and  there  is  no  danger  of  establishing  a  fistula. 

The  Renal  Arteries  arise  from  the  aorta  a  little  below  the 
transpyloric  plane.  The  right  one  passes  behind  the  vena  cava 
inferior,  the  head  of  the  pancreas,  the  second  part  of  the 
duodenum,  and  its  own  vein.  The  left  one  passes  behind  the 
body  of  the  pancreas  and  the  left  renal  vein. 

In  the  renal  sinus  the  terminal  branches  of  the  renal  artery 
divide  into  ventral  and  dorsal  groups.  Brodel  has  pointed  out 
that  an  incision  along  the  convex  lateral  margin  of  the  kidney 
cuts  through  the  principal  arteries  of  the  ventral  group,  and  he 
suggests  that  incisions  should  be  made  slightly  behind  that 


352  THE  ABDOMEN  AND   PELVIS 

border  so  as  to  pass  between  the  two  groups.  When  this  is 
done  successfully,  the  haemorrhage  is  not  so  great,  and  it  is 
easily  controlled  by  compression  of  the  vascular  pedicle. 

Supernumerary  renal  arteries  may  be  present  on  either  side. 
They  usually  arise  from  the  aorta  and  enter  the  medial  border 


FIG.  no. — Calculus  in  the  Renal  Pelvis.  The  twelfth  rib  is  almost  entirely 
obscured  by  the  large  calculus.  A  smaller  calculus  is  present  in  the 
lower  pole  of  the  kidney. 

of  the  kidney  near  its  lower  pole.  Sometimes  they  ascend  from 
the  common  iliac  or  they  may  arise  above  the  normal  renal  and 
enter  the  upper  pole.  Their  occurrence  must  always  be  borne 
in  mind  in  excision  of  the  kidney. 

i  .  The  Renal  Veins  terminate  in  the  inferior  vena  cava  at  the 
transpyloric  plane.  Owing  to  the  position  of  the  vena  cava  on 
the  right  side  of  the  vertebral  column,  the  right  renal  vein  is 
much  shorter  than  the  left,  and  it  is  consequently  liable  to  be 


THE  ABDOMINAL  CAVITY  353 

torn  away  from  the  vena  cava  during  the  manipulations  necessary 
in  excision  of  the  right  kidney.  The  left  renal  vein  lies  behind 
the  pancreas,  and  crosses  in  front  of  the  aorta  and  behind  the 
superior  mesenteric  artery.  It  receives  the  left  suprarenal  and 
the  left  spermatic  veins  (p.  264). 

Movable  Kidney. — Under  normal  conditions  the  kidney 
cannot  be  palpated,  although  it  moves  slightly  with  respiration. 
Sometimes  the  movement  may  become  so  increased  in  amount 
as  to  give  rise  to  distressing  symptoms  from  kinking  of  the 
ureter.  When  this  condition  is  suspected,  the  patient  should 
first  be  examined  in  the  recumbent  and  then  in  the  semi- 
recumbent -or  in  the  sitting  posture.  The  surgeon  places  one 
hand  in  the  interval  between  the  last  rib  and  the  iliac  crest 
and  the  other  on  the  anterior  abdominal  wall,  and  the  patient 
is  then  instructed  to  take  a  deep  breath.  As  the  abdominal 
wall  collapses  with  expiration,  the  surgeon  gently  presses  the 
tips  of  his  fingers  in  below  the  costal  margin  and  attempts  to 
catch  the  kidney  between  his  two  hands.  In  minor  degrees  of 
mobility  only  the  lower  pole  of  the  kidney  may  be  felt,  as  it 
slips  upwards  from  the  tips  of  the  fingers,  but  when  the  condition 
is  marked,  the  whole  kidney  may  be  caught,  or  the  fingers  may 
even  be  made  to  meet  above  its  upper  pole. 

The  right  kidney  is  more  often  at  fault  than  the  left,  and  a 
movable  right  kidney  must  not  be  confused  with  an  enlarged 
gall-bladder  (p.  313).  On  either  side  an  ovarian  cyst  which 
possesses  a  long  pedicle  may  be  mistaken  for  a  movable  kidney. 
This  is  owing  to  the  fact  that  the  surgeon,  on  examination,  is 
able  to  manipulate  the  tumour  into  the  position  which  the 
kidney  normally  occupies.  When  a  movable  kidney  has  been 
replaced  in  this  way,  it  tends  to  maintain  its  position,  but  an 
ovarian  cyst  soon  sinks  down  again  towards  the  pelvis. 

The  Ureter  is  about  ten  inches  long.  It  commences  at  the 
renal  pelvis  and  is  somewhat  constricted  at  its  point  of  origin. 
It  descends  on  the  anterior  surface  of  the  psoas  major,  which 
separates  it  from  the  tips  of  the  transverse  processes  of  the 
lumbar  vertebrae,  and  enters  the  pelvis  by  crossing  the  bifurcation 
of  the  common  iliac,  or  the  external  iliac  artery  near  its  com- 
mencement. 

On  the  right  side,  the  ureter  lies  behind  the  peritoneum  of 
the  right  infra-colic  compartment,  but  before  it  enters  the 
pelvis  it  is  crossed  by  the  root  of  the  mesentery  and  the  terminal 
part  of  the  ileum.  At  its  upper  end  it  lies  behind  the  second 

23 


354  THE  ABDOMEN  AND  PELVIS 

and  third  parts  of  the  duodenum ;  between  the  latter  and  the 
root  of  the  mesentery,  the  right  colic,  spermatic,  and  ileo-colic 
vessels  cross  its  anterior  surface  and  separate  it  from  the 
peritoneum  (Fig.  107).  On  account  of  these  relations  the 
lumbo-ilio-inguinal  route  (p.  274)  for  exposure  of  the  ureter  is 
to  be  preferred  to  the  trans-peritoneal  route. 

On  the  left  side,  the  ureter  lies  behind  the  peritoneum  of  the 
left  infra-colic  compartment,  and  as  it  enters  the  pelvis  it  is 
crossed  by  the  pelvic  meso-colon.  The  left  colic,  spermatic, 
and  sigmoid  vessels  cross  its  anterior  surface  (Fig.  107). 

The  blood-supply  of  the  ureter  is  derived  from  the  renal, 
spermatic,  superior,  and  inferior  vesical  arteries.  These  branches 
anastomose  freely  with  one  another,  and  as  a  result  large  segments 
of  the  ureter  can  be  freed  without  any  subsequent  sloughing. 

The  nerve-supply  of  the  renal  pelvis  and  the  ureter  is  derived 
from  the  eleventh  and  twelfth  thoracic  and  the  first  and  second 
lumbar  segments.  In  renal  colic  strong  waves  of  contraction 
pass  down  the  ureter,  and  the  pain  is  successively  referred  to 
the  skin  areas  supplied  by  these  segments.  When  the  calculus 
is  situated  in  the  renal  pelvis,  the  pain  begins  in  the  loin  in  the 
area  supplied  by  T.  n,  and  passes  obliquely  round  the  lower 
part  of  the  abdominal  wall  affecting  the  areas  supplied  by 
T.  12  and  L.  i  (ilio-hypogastric).  Sometimes  the  pain  shoots 
into  the  testis,  and  testicular  hypersesthesia  may  persist  after 
the  attack.  This  is  due  to  the  sensory  branch  which  the  external 
spermatic  (genital  branch  of  genito-crural)  nerve  (L.  i  and  2) 
gives  to  the  tunica  vaginalis  testis  (Mackenzie).  At  the  same 
time,  the  afferent  impulses  from  the  strongly  contracting  ureter 
may  excite  a  viscero-motor  reflex  (p.  251).  The  lower  portions 
of  the  lateral  abdominal  muscles  become  rigid,  and  the  cremaster 
muscle  may  contract  and  draw  the  testis  up  towards  the 
subcutaneous  inguinal  ring.  All  the  muscles  affected  are 
innervated  from  the  same  segments  as  supply  the  skin  areas 
over  which  the  pain  is  felt.  The  viscero-sensory  reflex  may 
also  affect  the  lumbo-inguinal  nerve  (crural  branch  of  genito- 
crural)  and  the  posterior  rami  of  the  upper  lumbar  nerves  so 
that  pain  is  experienced  in  the  front  of  the  thigh  and  in  the 
buttock. 


THE  PELVIS  355 


THE  PELVIS. 

The  Pelvis  Minor  (True  Pelvis).— The  walls  of  the 
pelvis  consist  of  three  layers :  (i)  a  bony  and  ligamentous 
stratum,  (2)  a  muscular  stratum,  and  (3)  a  fascial  stratum. 

1.  The  osseous  circle,  formed  by  the  sacrum,  the  coccyx, 
and  the  hip  bones,  is  strengthened  by  the  sacro-tuberous  and 
sacro-spinous  ligaments  (great  and  small  sacro-sciatic),  which 
connect  the  sacrum  and  coccyx  with  the  ischium.     In  the  pubic 
arch  this  layer  is  represented  by  the  inferior  fascia  of  the 
urogenital  diaphragm  (anterior  layer  of  triangular  ligament). 

2.  The  muscular  layer  consists  of  :  (a)  the  obturator  internus, 
which  arises  from  the  side  wall  of  the  pelvis  and  passes  through 
the  lesser  sciatic  foramen  (p.  419) ;  (b)  the  piriformis,  which  arises 
from  the  front  of  the  sacrum  and  passes  through  the  greater 
sciatic  foramen ;    and  (c)  the  sphincter  of  the  membranous 
urethra  (compressor  urethrae),  which  assists  in  rilling  the  gap 
between  the  inferior  rami  of  the  pubes. 

3.  The  fascia  which  covers  these  muscles  is  termed  the 
parietal  pelvic  fascia.    It  is  continuous  above  with  the  fascia 
lining  the  abdomen  and  is  attached  below  to  the  margins  of 
the  inferior  pelvic  aperture. 

The  large  nerves  of  the  lumbo-sacral  and  sacro-coccygeal 
plexuses  lie  between  the  muscular  and  fascial  strata,  but  the 
large  blood-vessels  -lie  under  the  peritoneum  internal  to  the 
fascia,  and  with  the  exception  of  the  obturator  artery  (p.  411), 
pierce  it  as  they  leave  the  pelvis  through  the  various  foramina. 
The  points  at  which  they  pass  through  the  fascia  are  the  sites 
of  pelvic  hernise. 

Fractures  of  the  Pelvis  are  usually  caused  by  severe 
crushing,  and  they  occur  at  the  weakest  areas  of  the  bony  ring, 
namely,  the  pubic  and  ischial  rami,  where  they  bound  the 
obturator  foramen,  and  the  sacrum,  along  the  line  of  the  sacral 
foramina.  Rectal  or  vaginal  examination  will  often  disclose 
the  extent  of  the  fracture  and  may  assist  the  surgeon  to  obtain 
the  correct  alignment  of  the  displaced  fragments.  Serious 
complications  arise  if  the  sharp  broken  edges  wound  any  of  the 
pelvic  viscera. 

The  Parietal  Pelvic  Fascia  covers  the  piriformis,  the  ob- 
turator internus,  and  the  sphincter  of  the  membranous  urethra. 


356  THE  ABDOMEN  AND  PELVIS 

The  obturator  internus  arises  from  the  posterior  part  of  the 
ilio-pectineal  line,  and  over  this  area  the  parietal  pelvic  fascia 
is  directly  continuous  with  the  abdominal  fascia  covering  the 
psoas  major  (p.  271).  More  anteriorly,  the  upper  border  of 
the  obturator  internus  gradually  sinks  to  a  lower  level  and 
carries  the  parietal  pelvic  fascia  with  it ;  so  that  the  inner 
surface  of  the  superior  ramus  of  the  pubis  is  left  uncovered  by 
fascia  or  muscle.  Opposite  the  obturator  foramen,  the  fascia 
is  carried  over  the  upper  border  of  the  obturator  internus 
and  blends  with  the  upper  margin  of  the  obturator  membrane. 
In  the  region  of  the  pubic  arch  it  forms  the  superior  fascia  of 
the  urogenital  diaphragm  (deep  layer  of  triangular  ligament] 
(Fig.  115),  and  its  upper  border  blends  with  the  upper  border  of 
the  inferior  fascia  of  the  urogenital  diaphragm  (p.  378),  leaving 
a  small  interval  below  the  pubic  symphysis  for  the  passage  of 
the  dorsal  vein  of  the  penis. 

The  lower  margin  of  the  parietal  pelvic  fascia  blends,  in 
front,  with  the  free  edge  of  the  inferior  fascia  of  the  urogenital 
diaphragm  and  the  fascia  of  Colles  (p.  376) ;  posteriorly,  it 
is  attached  to  the  sacro-tuberous  ligament  and  the  ischial 
tuberosity. 

The  Pelvic  Diaphragm  stretches  across  the  cavity  of  the 
pelvis,  dividing  it  into  an  upper  part,  the  pelvis  proper,  and  a 
lower  part,  which  is  dealt  with  under  the  Perineum  (p.  373). 
It  is  formed  by  the  two  levatores  ani  and  coccygei,  with  the  fascia 
covering  them,  but  it  is  incomplete,  as  gaps  are  left  for  the 
passage  of  the  anal  canal  and  the  urethra  and,  in  the  female, 
for  the  vagina  also. 

The  Levator  Ani  has  a  linear  origin  from  the  side  wall  of  the 
pelvis.  Its  posterior  fibres  are  attached  to  the  ischial  spine ; 
the  intermediate  fibres  arise  from  the  parietal  pelvic  fascia 
along  a  line  extending  from  the  ischial  spine  to  the  anterior 
border  of  the  obturator  foramen.  The  anterior  fibres  arise 
from  the  pelvic  surface  of  the  body  of  the  pubis  above  the  level 
of  the  parietal  pelvic  fascia,  but  they  do  not  extend  as  far  as 
the  symphysis. 

The  posterior  fibres  pass  medially  and  are  inserted  into  the 
coccyx.  In  front  of  that  point  the  muscles  of  the  two  sides 
meet  in  a  median  raphe  and  form  a  muscular  sling,  which 
supports  the  lower  end  of  the  rectum.  The  anterior  fibres  pass 
backwards  lateral  to  the  prostate,  which  separates  them  from 
the  muscle  of  the  opposite  side,  and  they  extend  downwards 


THE  PELVIS  357 

along  the  outer  surface  of  the  anal  canal  to  blend  with  its 
muscular  coat  between  the  internal  and  external  sphincters 

(P-  369)- 

A  collection  of  muscular  fibres  extending  antero-posteriorly 

between  the  pelvic  surface  of  the  urogenital  diaphragm  and 
the  upper  end  of  the  anal  canal  is  termed  the  Recto-urethralis 
muscle  (p.  369). 

In  the  female  the  anterior  borders  of  the  two  leva  tores  ani 
pass  one  on  each  side  of  the  vagina  and  act  as  a  sphincter 
muscle. 

The  principal  action  of  the  levator  ani  is  to  assist  defgecation 
by  drawing  the  anal  canal  upwards  over  the  fsecal  mass,  thus 
assisting  in  its  expulsion. 

Its  nerve-supply  is  derived  from  the  perineal  division  of  the 
internal  pudendal  (S.  2,  3,  4)  and  directly  from  S.  3  and  4. 

The  Coccygeus  is  a  small  muscle  which  overlaps  the  posterior 
border  of  the  levator  ani.  It  extends  from  the  ischial  spine  to 
the  sides  of  the  sacrum  and  coccyx,  and  helps  to  complete  the 
pelvic  floor. 

The  Visceral  Pelvic  Fascia  forms  the  upper  layer  of  the 
pelvic  diaphragm  and  covers  the  pelvic  surfaces  of  the  levatores 
ani  and  the  coccygei.  Opposite  the  pubic  symphysis,  where 
the  two  levatores  leave  a  gap,  the  fascia  forms  a  continuous 
sheet  from  side  to  side.  It  is  very  weak  in  the  middle  line,  but 
is  specially  thickened  at  each  side,  where  it  extends  backwards 
to  the  prostate  and  the  bladder,  forming  the  true  pub o-pro static 
ligaments  (anterior  pedicles  of  the  bladder).  Elsewhere,  its 
circumferential  attachment  corresponds  to  the  linear  origin 
of  the  muscles  of  the  pelvic  diaphragm. 

When  it  is  traced  inwards  from  the  sides,  it  is  found  to  be 
in  contact  with  the  various  pelvic  viscera,  which  it  provides 
with  fibrous  coverings.  On  account  of  this  relationship  the 
visceral  pelvic  fascia  is  described  as  consisting  of  rectal,  recto- 
vesical,  and  vesical  portions. 

Anteriorly  the  visceral  pelvic  lascia  is  specially  thickened  to 
form  a  strong  fibrous  sheath  for  the  prostate  gland. 

The  Pelvic  Peritoneum  is  separated  from  the  pelvic  dia- 
phragm by  the  pelvic  viscera  and  blood-vessels.  It  covers  the 
front  and  sides  of  the  upper  two-thirds  of  the  rectum  (p.  368) 
and  is  then  reflected  forwards  on  to  the  upper  part  of  the 
posterior  surface  of  the  urinary  bladder,  forming  the  floor  of 
the  recto-vesical  fossa.  It  covers  the  superior  surface  of  the 


358  THE  ABDOMEN  AND  PELVIS 

bladder  and  is  reflected  from  its  apex  on  to  the  anterior  abdominal 
wall. 

The  Urinary  Bladder  occupies  the  anterior  part  of  the 
pelvic  basin  and  lies  immediately  behind  the  pubes.  When 
empty  it  is  somewhat  pyramidal  in  shape,  with  an  apex,  a  base, 
a  superior,  and  two  infero-lateral  surfaces. 

The  apex  of  the  bladder  is  directed  forwards  and  upwards 
and  is  in  contact  with  the  pubic  symphysis.  An  impervious 
fibrous  cord,  known  as  the  urachus  (p.  381),  passes  upwards 
from  the  apex  to  the  umbilicus  in  the  extra-peritoneal  fat. 

The  base  or  posterior  surface  is  directed  backwards  and 

,.  Ureter 


___  Membranous  urethra 


FIG.  in. — Basal  aspect  of  Bladder,  Seminal  Vesicles,  and  Prostate, 
hardened  by  formalin  injection. 

slightly  downwards  towards  the  rectum.  It  is  roughly  triangular 
in  shape  ;  the  inferior  angle  is  truncated  and  corresponds  to  the 
internal  orifice  of  the  urethra,  while  the  supero-lateral  angles 
are  joined  by  the  ureters.  In  the  middle  line  the  two  ductus 
deferentes  lie  side  by  side  in  apposition  with  this  surface  and 
separate  the  seminal  vesicles  from  one  another  (Fig.  in).  These 
parts  of  the  genital  tract  are  embedded  in  visceral  pelvic  fascia 
and  intervene  between  the  basal  surface  of  the  bladder  and  the 
rectum.  A  small  interval,  however,  exists  between  the  ductus 
deferentes  near  the  upper  border,  and  it  slightly  increases  in 
size  as  the  bladder  becomes  distended.  Through  this  area  the 
trochar  was  passed  in  puncture  of  the  bladder  by  the  old-fashioned 
rectal  route. 


THE  PELVIS  359 

The  superior  surface  is  entirely  covered  by  peritoneum 
and  is  related  to  coils  of  small  intestine  or  pelvic  colon.  Along 
its  lateral  borders  the  peritoneum  is  reflected  on  to  the  pelvic 
walls  as  the  so-called  lateral  false  ligaments  of  the  bladder. 

The  infero-lateral  surfaces  are  related  in  front  to  the  bodies 
of  the  pubes  and  the  retro-pubic  pad  of  fat.  Posteriorly  they 
are  in  contact  with  the  upper  parts  of  the  obturator  internus  and 
levator  ani  muscles. 

The  neck  of  the  bladder  is  situated  where  the  infero-lateral 
and  posterior  surfaces  meet  one  another.  It  is  pierced  by  the 
urethra  and  is  partly  continuous  with  the  prostate. 

When  the  bladder  distends,  it  becomes  more  or  less  ovoid  in 
shape.  The  neck  and  posterior  surface  are  not  much  affected 
but  the  infero-lateral  and  superior  surfaces  become  greatly 
stretched,  and  the  upper  part  of  the  bladder  comes  to  lie  in  the 
abdomen.  This  increase  in  size  does  not  involve  any  stretching 
of  the  vesical  peritoneum,  for,  as  the  bladder  rises  into  the 
abdomen,  it  strips  the  peritoneum  off  the  lateral  pelvic  and 
anterior  abdominal  walls.  In  this  way  the  anterior  part  of  the 
infero-lateral  surfaces  comes  to  lie  in  direct  contact  with  the 
anterior  abdominal  wall,  no  peritoneum  intervening.  In  aspirat- 
ing the  over-distended  bladder  supra-pubically,  the  surgeon  takes 
advantage  of  this  alteration  in  the  disposition  of  the  peritoneum, 
and  in  the  operation  of  supra-pubic  cystotomy  the  same  condition 
is  obtained  by  distending  the  bladder  artificially. 

In  the  infant,  the  bladder  occupies  a  higher  position  than  it 
does  in  the  adult  owing  to  the  smaller  relative  size  of  the  pelvis 
and  the  greater  relative  size  of  the  bladder  itself.  The  internal 
orifice  of  the  urethra  lies  almost  on  a  level  with  the  upper  border 
of  the  pubic  symphysis,  and  most  of  the  bladder  is  situated  in  the 
abdomen.  This  difference  must  be  borne  in  mind  when  opening 
the  abdomen  in  the  infant,  and  care  should  be  taken  to  see  that 
the  bladder  is  evacuated  before  making  an  incision  in  the  lower 
part  of  the  anterior  abdominal  wall. 

The  retro -pubic  pad  of  fat  occupies  the  space  of  Retzius, 
which  is  bounded  in  front  by  the  symphysis  pubis,  behind  by 
the  bladder,  and  below  by  the  true  pubo-prostatic  ligaments. 
In  extra-peritoneal  rupture  of  the  bladder  the  extra vasated  urine 
collects  temporarily  in  this  space  (p.  378). 

Supra -Pubic  Cystotomy  is  commonly  performed  for  the 
removal  of  calculi,  tumours,  and  soft,  enlarged  prostates  capable 
of  easy  enucleation.  The  bladder  is  emptied,  and  then  filled 


360  THE  ABDOMEN  AND  PELVIS 

with  warm  boracic  lotion  as  a  preliminary  measure,  its  capacity 
having  been  estimated  prior  to  anaesthesia  so  as  to  exclude  the 
risk  of  over-distension.  In  this  way  the  bladder  is  brought  into 
direct  contact  with  the  lower  part  of  the  anterior  abdominal 


FIG.  112  — Vesical  Calculus,  Antero-posterior  View.     Observe  the  positions 
of  the  calculus  and  the  ischial  spines  relative  to  the  sacrum. 

wall,  no  peritoneum  intervening  (p.  359).  A  transverse  incision, 
about  four  inches  long,  is  made  a  little  above  the  pubes  This 
passes  through  the  skin  and  fasciae  and  exposes  the  linea  alba 
and  both  rectus  sheaths.  A  vertical  incision  is  made  in  the  linea 
alba,  and  the  two  recti  are  retracted.  If  satisfactory  access  is 
not  obtained,  the  muscles  may  be  elevated  from  their  pubic 
attachments  so  that  they  can  be  more  widely  separated. 


THE  PELVIS  361 

The  fascia  transversalis  is  divided  and  the  bladder  is  exposed 
in  the  extra-peritoneal  fat.  The  fingers  are  then  passed  upwards 
until  the  line  of  peritoneal  reflection  is  met,  and  the  peritoneum 
is  then  further  elevated  from  the  bladder.,  In  order  to  prevent 
the  bladder  from  collapsing  into  the  pelvis  when  it  is  incised, 
two  retention  sutures  are  passed  through  its  wall  and  are  held 
by  an  assistant  during  the  operation.  The  bladder  may  now 
be  incised,  and  the  calculus,  tumour,  etc.,  removed. 

The  muscular  coat  of  the  bladder  is  very  strongly 
developed.  Near  the  neck  the  outer  fibres  become  continuous 
with  the  muscular  tissue  of  the  prostate ;  the  intermediate 
fibres  are  increased  in  number  and  form  the  sphincter  vesicse 
internus ;  the  inner  layer  becomes  continuous  with  the 
longitudinal  muscular  coat  of  the  urethra. 

The  mucous  lining  of  the  bladder  is  not  so  elastic  as 
the  muscular  coat,  and  is  thrown  into  rugae  when  the  bladder  is 
empty.  This  is  permitted  by  the  laxity  of  the  submucosa  ;  but 
over  a  triangular  area  which  corresponds  to  the  basal  surface, 
the  mucous  coat  is  smooth  and  firmly  adherent  to  the  muscular 
wall.  This  area  is  referred  to  as  the  internal  trigone  :  its  superior 
angles  correspond  to  the  openings  of  the  ureters,  and  its  inferior 
angle  to  the  internal  orifice  of  the  urethra,  which  is  i\  inches 
from  the  opening  of  either  ureter.  The  ureters  pierce  the 
bladder  wall  very  obliquely,  and  when  the  intra-vesical  pressure 
is  increased  as  the  bladder  fills,  this  arrangement  provides  a 
valve -like  action,  which  prevents  a  reverse  flow  towards  the 
kidneys.  The  ureteral  openings  are  about  two  inches  apart  and 
are  connected  by  a  ridge  of  mucous  membrane  called  the  inter- 
ureteric  bar. 

In  hypertrophy  of  the  muscular  coat}to  overcome  the  obstruction 
caused  by  stricture  of  the  urethra,  prostatic  enlargement,  etc., 
small  pockets  of  mucous  membrane  may  be  formed  in  the 
intervals  between  the  bands  of  enlarged  fibres.  These  loculi 
sometimes  form  distinct  diverticula,  and  they  tend  to  retain 
urine,  which  decomposes  and  gives  rise  to  calculus  formation. 
The  presence  of  incarcerated  stones  in  the  bladder  wall  can  be 
accounted  for  in  this  way. 

The  Arteries  of  the  bladder  are  derived  from  the  hypogastric 
(internal  iliac)  artery  by  means  of  three  paired  vessels,  the 
superior,  middle,  and  inferior  vesical  arteries. 

Together  with  the  ureter,  lymphatics,  and  nerves,  the 
arteries  and  veins  of  each  side  are  embedded  in  a  sheet  of  visceral 


362  THE  ABDOMEN  AND  PELVIS 

pelvic  fascia,  which  passes  forwards  and  medially  to  the  lateral 
border  of  the  posterior  surface  of  the  bladder  and  constitutes 
its  posterior  pedicle. 

The  vesical  arteries  supply  the  bladder,  the  seminal  vesicles, 
the  prostate  and  the  terminal  parts  of  the  ureters.  In  addition 
the  superior  vesical  usually  gives  off  a  special  branch  to  the 
ductus  deferens  (p.  257). 

The  vesical  veins  join  the  pudendal  (prostatic)  plexus  (p.  366), 
from  which  two  or  three  large  veins  issue  in  the  posterior  pedicle 
of  the  bladder  to  join  the  hypogastric  vein. 

The  nerve-supply  of  the  bladder  is  derived  entirely  through 
the  sympathetic.  Some  of  the  fibres  come  from  the  twelfth 
thoracic  and  first  lumbar  segments  ;  the  others  arise  from  the 
second  and  third,  or  third  and  fourth  sacral  segments,  and  are 
restricted  to  the  basal  surface  and  the  trigone.  On  account 
of  the  different  segments  involved,  pain  referred  from  the 
bladder  is  felt  in  two  different  regions.  A  vesical  calculus 
irritates  the  trigone,  and  the  pain  is  referred  to  the  perineum 
and  the  penis  (S.  2,  3,  and  4).  On  the  other  hand,  pain  due  to 
over-distension  or  caused  by  strong  contraction  of  the  muscular 
wall,  such  as  occurs  at  the  end  of  micturition  in  cases  of  vesical 
calculus,  is  usually  referred  to  the  lower  part  of  the  anterior 
abdominal  wall  (T.  12,  L.  i). 

In  the  presence  of  vesical  calculi  or  ulcers  of  the  bladder 
wall,  the  centres  for  micturition  in  the  spinal  medulla  become 
hypersensitive,  and  frequency  of  micturition  results. 

The  Pelvic  Part  of  the  Ureter  is  closely  related  to  the 
peritoneum.  It  crosses  the  brim  of  the  pelvis  in  front  of,  or  a 
little  lateral  to,  the  bifurcation  of  the  common  iliac  artery,  and 
descends  in  front  of  the  hypogastric  (internal  iliac)  artery,  which 
separates  it  from  the  posterior  wall  of  the  pelvis  and  the  great 
nerve  trunks.  As  it  approaches  the  base  of  the  bladder,  it 
curves  medially  and  enters  the  posterior  pedicle.  Here  it  is 
related  to  the  superior  vesical  artery,  which  lies  above  it,  and 
the  other  vesical  arteries  and  veins,  which  lie  below  it.  Just 
before  entering  the  bladder  (p.  358),  the  ureter  is  crossed 
latero-medially  and  on  its  superior  aspect  by  the  ductus  deferens, 
which  intervenes  between  it  and  the  peritoneum. 

This  part  of  the  ureter  is  supplied  by  the  vesical  arteries. 

Impacted  calculi  in  the  pelvic  part  of  the  ureter  are  usually 
found  (i)  at  the  pelvic  brim,  on  a  level  with  the  first  sacral 
vertebra,  or  (2)  at  the  point  of  entrance  into  the  bladder,  on  a 


THE  PELVIS 


363 


level  with  the  first  coccygeal  vertebra,  because  the  lumen  of 
the  tube  is  distinctly  narrower  at  these  two  points.  When  a 
radiogram  shows  a  shadow  which  might  be  an  ureteral  calculus, 
its  horizontal  level  is  of  as  great  importance  as  its  vertical  plane 
as  an  aid  to  differential  diagnosis. 


FIG.  113. — Radiogram  showing  the  lower  abdominal  and  the  pelvic  portions 
of  the  Ureters,  displayed  by  the  introduction  of  bougies. 

The  surgical  approach  for  the  removal  of  an  impacted  ureteral 
calculus  may  be  either  retro-peritoneal  or  infra-peritoneal. 

Calculi  impacted  near  the  pelvic  brim  are  best  approached 
by  the  retro -peritoneal  route  (p.'  274). 

Infra-peritoneal  Route. — In  order  to  obtain  access  to  the 
terminal  part  of  the  ureter,  an  oblique  incision,  which  is  directed 
downwards  and  medially,  is  made  through  the  lower  part  of 
the  anterior  abdominal  wall^(Fig.  71).  In  its  medial  two-thirds 
this  incision  crosses  the  rectus  muscle  below  the  level  of  the 
linea  semicircularis  (of  Douglas).  The  aponeuroses  of  the 


364  THE  ABDOMEN  AND  PELVIS 

external  oblique,  internal  oblique,  and  transversus  are  divided, 
in  turn,  in  the  lateral  part  of  the  wound,  whilst  medially  the 
anterior  wall  of  the  rectus  sheath  is  divided  and  the  muscle  is 
retracted  in  a  medial  direction.  The  transversalis  fascia  is 
now  exposed,  and  the  inferior  epigastric  artery,  which  may  be 
ligated  if  necessary,  is  found  on  its  surface  in  the  medial  part 
of  the  wound. 

The  fascia  transversalis  is  torn  through  in  the  neighbourhood 
of  the  bladder,  and  the  peritoneum  is  retracted  upwards  and 
medially.  In  this  way  the  abdominal  viscera  are  kept  out  of 
the  field  of  operations  and  more  space  is  obtained.  When  the 
peritoneum  is  elevated,  the  external  iliac  vessels  are  exposed  in 
the  posterior  part  of  the  wound,  and  the  ductus  deferens  is  seen 
in  front,  as  it  descends  to  reach  the  seminal  vesicles  (p.  358). 
In  this  part  of  its  course  the  ureter  is  not  adherent  to  the 
peritoneum,  but  is  closely  related  to  the  structures  on  the  pelvic 
wall.  The  superior  vesical  artery  forms  a  convenient  guide, 
since  it  lies  anterior  to  the  ureter.  As  a  small  calculus,  impacted 
in  the  terminal  portion  of  the  ureter,  may  be  extremely  difficult 
to  feel,  an  assistant  pushes  the  bladder  upwards  by  means  of 
a  finger  in  the  rectum.  The  surgeon  then  presses  the  ureter 
against  the  resistance  thus  afforded,  and  determines  the  precise 
position  of  the  stone. 

Calculi  impacted  in  the  vesical  orifice  of  the  ureter  may  be 
removed  trans-vesically  (cf.  removal  of  gall-stones  impacted  in 
ampulla  of  Vater,  p.  317). 

The  Prostate  consists  chiefly  of  plain  muscle  fibres  and 
glandular  tissue,  surrounded  by  a  fibrous  capsule.  The  muscle 
fibres  are  directly  continuous  with  the  external  stratum  of  the 
muscular  coat  of  the  bladder.  The  prostate  possesses  a  strong 
fibrous  sheath,  which  is  derived  from  the  visceral  pelvic  fascia 
and  is  quite  distinct  from  the  capsule.  This  sheath  does  not 
intervene  between  the  prostate  and  the  bladder,  but  is  carried 
upwards  on  to  the  walls  of  the  latter. 

In  size  and  shape  the  prostate  resembles  a  chestnut.  Its 
base  is  directed  upwards  and  is  partly  continuous  with  the  neck 
of  the  bladder  ;  its  apex  is  directed  downwards  and  rests  on  the 
superior  fascia  of  the  urogenital  diaphragm.  The  posterior  surface 
is  in  contact  with  the  rectum  and  can  readily  be  palpated  on  rectal 
examination.  The  lateral  surface  is  crossed  by  the  anterior  border 
of  the  levator  ani  and  can  also  be  examined  from  the  rectum. 

The  prostate  encloses  the  first  part  of  the  urethra,  which 


THE  PELVIS  365 

pierces  its  base,  traverses  its  substance,  and  emerges  a  little 
above  its  apex.  It  is  also  pierced  by  the  common  ejaculatory 
ducts  (p.  367). 

A  well-marked  groove  separates  the  prostate  from  the 
bladder  externally.  At  this  level  the  prostatic  sheath  contains 
in  its  walls  the  pudendal  (prostatico-vesical)  plexus  of  veins,  which 
receives  the  dorsal  vein  of  the  penis  (p.  386),  and  tributaries 
from  the  bladder  and  prostate.  The  prostatic  veins  cross  the 
potential  interval  between  the  capsule  and  the  sheath  to  reach 
the  plexus,  and  are  consequently  torn  in  prostatectomy. 
(Compare  this  arrangement  with  the  course  of  the  thyreoid 
veins,  p.  168.) 

The  pudendal  plexus  terminates  in  the  large  veins  which 
have  already  been  mentioned  in  connection  with  the  posterior 
pedicle  of  the  bladder  (p.  362). 

Hypertrophy  of  the  Prostate  usually  involves  the  glandular 
tissue,  and  may  be  confined  to  the  "  middle  lobe  "  ;  but  the  whole 
prostate  may  become  enlarged.  The  dense,  unyielding  character 
of  the  sheath  limits  the  growth  in  antero-posterior  and  lateral 
directions,  but  the  neck  of  the  bladder  offers  little  resistance 
to  upward  extension.  As  a  result  the  prostatic  tissue  projects 
into  the  bladder  through  the  internal  sphincter  and  forms  a 
collar-like  elevation  around  the  internal  urethral  orifice.  The 
muscular  tissue  which  connects  the  prostate  and  the  bladder  is 
stretched  and  thinned  out,  so  that  few  or  no  fibres  are  encountered 
by  the  surgeon  in  prostatectomy  (p.  366),  and  the  tumour  is 
exposed  as  soon  as  the  mucous  membrane  over  it  has  been  torn 
through. 

Owing  to  the  direction  of  growth  the  prostatic  urethra 
becomes  increased  in  length  from  ij  to  2  or  2^  inches,  and  at 
the  same  time  its  forward  concavity  becomes  proportionately 
greater. 

The  so-called  "  middle  lobe  "  of  the  prostate  is  that  part 
which  intervenes  between  the  ejaculatory  ducts  (p.  367)  and 
the  urethra.  Its  upper  surface  lies  under  the  mucous  coat 
of  the  tiigone  of  the  bladder,  immediately  behind  the  internal 
urethral  orifice,  and  when  well  marked  produces  a  slight  elevation 
known  as  the  uvula  vesicce.  When  hypertrophy  affects  the 
middle  lobe  only,  the  prostate  is  apparently  normal  on  rectal 
examination.  In  these  cases  the  enlarged  uvula  seriously 
hinders  the  escape  of  urine  through  the  internal  urethral  orifice 
and  constitutes  one  of  the  worst  forms  of  urinary  obstruction. 


366  THE  ABDOMEN  AND  PELVIS 

Effects  of  Prostatic  Hypertrophy.  —  The  upward  growth 
of  the  prostate  weakens  the  internal  sphincter  of  the  bladder 
so  that  urine  enters  the  urethra  more  easily  and  the  desire  to 
micturate  is  more  frequent. 

A  pouch  gradually  forms  behind  the  collar -like  elevation 
which  surrounds  the  internal  urethral  orifice,  and  the  urine 
which  it  contains  can  only  be  evacuated  by  straining.  As  the 
tumour  increases  in  size,  the  pouch  becomes  deeper  and  attempts 
to  evacuate  it  merely  crush  down  the  projection  over  the  orifice 
of  the  urethra.  The  urine  in  this  part  of  the  bladder  cannot 
be  passed,  and  is  termed  "  residual  urine."  The  straining 
causes  hypertrophy  of  the  muscular  wall,  and  for  a  time  this 
may  assist  micturition.  Ultimately,  however,  the  increasing 
amount  of  residual  urine  leads  to  dilatation  of  the  bladder, 
and  urine  can  only  be  passed  by  the  contraction  of  the  abdominal 
muscles.  The  quantity  passed  at  one  time  is  necessarily  small, 
so  that  the  bladder  remains  constantly  distended.  This 
condition  may  come  on  very  gradually,  and  the  patient,  being 
totally  unaware  of  its  nature,  only  complains  of  symptoms 
which  are  referable  to  chronic  auto-intoxication. 

Attacks  of  prostatic  congestion  are  followed  by  complete 
retention  of  urine  and  still  further  dilatation  of  the  bladder, 
which  may  never  regain  its  muscular  tone.  The  rapid  evacuation 
of  a  greatly  distended  and  dilated  bladder  by  the  passage  of  a 
catheter  may  be  followed  by  severe  haemorrhage,  as  the  weakened 
muscular  wall,  when  relieved  of  its  internal  pressure,  is  unable 
to  contract,  and  the  vessel-walls,  being  unsupported,  give  way. 

Supra-Pubic  Prostatectomy.  —  A  catheter  is  first  passed 
into  the  bladder,  and  the  viscus  is  then  opened  by  the  method 
outlined  on  p.  359.  The  surgeon  inserts  his  finger,  and  guided 
to  the  internal  urethral  orifice  by  the  instrument,  he  scrapes 
through  the  mucous  coat  overlying  the  prostate  with  his  finger- 
nail. At  the  same  time  the  surgeon  may  pass  the  index  finger 
of  his  free  hand,  suitably  protected,  into  the  rectum  and  use  it 
as  a  guide  and  support  for  his  manipulations  inside  the  bladder. 
Owing  to  the  thinning  out  of  the  muscular  tissue  (p.  365)  the 
tear  in  the  mucous  coat  at  once  exposes  the  prostate,  and 
the  surgeon  thrusts  his  finger  through  into  the  interval  between 
the  capsule  and  the  sheath.  This  interval  is  defined  by  sweeping 
the  finger  first  round  one  side  of  the  prostate  and  then  round  the 
other.  In  the  process  the  prostatic  veins  are  torn  through  as 
they  pass  outwards  to  join  the  pudendal  plexus.  The  prostate 


THE  PELVIS  367 

is  now  only  fixed  by  the  distal  end  of  the  prostatic  urethra, 
and  this  is  torn  across  as  it  pierces  the  urogenital  diaphragm. 

If  the  surgeon  fails  to  define  the  interval  between  the  capsule 
and  the  sheath  and  penetrates  the  latter  with  his  finger-nail, 
severe  haemorrhage  results  from  the  thin-walled  veins  of  the 
pudendal  plexus  and  its  vesical  tributaries.  The  condition  is 
accentuated  if  the  surgeon  continues  to  attempt  enucleation 
with  his  finger  in  the  wrong  stratum. 

b  Drainage  is  obtained  by  a  wide  supra-pubic  tube,  but  in  the 
presence  of  cystitis  some  surgeons  make  use  of  a  perineal  drain 
in  addition.  A  pair  of  long  forceps  is  inserted  through  the 
supra-pubic  wound  into  the  cavity  of  the  prostatic  sheath  and 
cut  down  on  in  the  perineum.  A  tube  is  then  drawn  upwards, 
and  the  whole  cavity  can  be  washed  out  thoroughly.  An 
advantage  of  this  additional  drain  is  that  it  prevents  absorption 
from  the  accumulation  of  septic  urine  and  blood-clot  in  the  raw 
area. 

As  a  result  of  the  removal  of  the  prostate,  the  first  part  of 
the  urethra  is  replaced  by  a  fibrous  sac — the  prostatic  sheath. 
The  neck  of  the  bladder  opens  into  it  above  and  the  urethra 
opens  out  from  it  below.  This  cavity  soon  collapses  and  its 
walls  gradually  become  lined  by  mucous  membrane,  which  grows 
upwards  from  the  torn  urethra  and  downwards  from  the  bladder. 

The  Seminal  Vesicles  lie  obliquely  on  the  basal  surface  of 
the  bladder  •  their  upper  extremities  are  widely  separated  and 
their  lower  extremities  are  close  together.  Posteriorly,  they 
are  related  to  the  anterior  surface  of  the  rectum,  and  only 
visceral  pelvic  fascia  intervenes.  The  upper,  blind  end  of  the 
seminal  vesicle  lies  immediately  under  the  floor  of  the  recto- 
vesical  peritoneal  fossa  and  close  to  the  termination  of  the 
ureter.  Its  lateral  border  is  closely  applied  to  the  medial 
aspect  of  the  posterior  pedicle  of  the  bladder,  and  its  medial 
border  is  related  to  the  ductus  deferens  (Fig.  in). 

Inferiorly  the  seminal  vesicle  narrows  to  form  the  excretory 
duct,  which  joins  the  ductus  deferens  to  form  the  common 
ejaculatory  duct.  The  two  ejaculatory  ducts  pass  downwards 
and  forwards  through  the  substance  of  the  prostate  and  open 
into  the  prostatic  urethra  close  to  the  orifice  of  the  prostatic 
utricle  (p.  383). 

The  Rectum  begins  opposite  the  third  piece  of  the  sacrum 
as  the  direct  continuation  of  the  descending  limb  of  the  pelvic 
colon.  It  is  about  five  inches  long  and  curves  downwards  and 


368  THE  ABDOMEN  AND  PELVIS 

forwards  to  a  point  a  little  above  the  apex  of  the  prostate, 
where  it  bends  sharply  backwards  and  downwards,  over  the 
anterior  decussating  fibres  of  the  levatores  ani,  to  form  the  anal 
canal.  The  expanded  lower  part  of  the  rectum  is  termed  the 
ampulla  and  is  better  marked  in  the  female  than  in  the  male. 

In  its  upper  third  the  rectum  is  clothed  by  peritoneum 
anteriorly  and  on  each  side  ;  in  its  middle  third  it  is  only  covered 
anteriorly ;  its  lower  third  lies  below  the  line  of  reflection  of 
the  peritoneum  from  the  rectum  to  the  bladder  (p.  357)  and  is 
consequently  devoid  of  any  peritoneal  covering  (Fig.  115). 
The  upper  two-thirds  of  the  rectum  is  related  anteriorly  to  the 
coils  of  small  intestine,  or  pelvic  colon,  which  occupy  the  recto- 
vesical  fossa  and  separate  it  from  the  bladder,  and  tumours  of 
the  pelvic  colon  may  sometimes  be  palpated  per  rectum.  In 
front  of  the  lower  third  of  the  rectum  lie  the  seminal  vesicles, 
ductus  deferentes  and  the  prostate,  embedded  in  visceral  pelvic 
fascia  (Fig.  115). 

As  it  descends  following  the  curvature  of  the  sacrum  and 
coccyx,  the  rectum  exhibits  three  lateral  flexures ,  the  uppermost 
and  lowermost  being  directed  to  the  left  and  the  middle  one 
to  the  right.  As  a  result,  the  rectum  is  not  median  in  position 
but  projects  to  the  left  side  of  the  middle  line.  On  the  concavity 
of  each  bend,  a  crescentic  fold,  consisting  of  the  mucous  and 
circular  muscular  coats,  projects  within  the  lumen  of  the  gut 
and  stretches  almost  halfway  round  it.  These  folds  are  known 
as  the  plicce  transversales  recti  (rectal  valves),  and  they  serve  to 
support  the  faeces  and  to  prevent  over-distension  of  the  ampulla. 
Scybalous  masses  supported  by  the  lowest  fold,  which  lies  at 
about  three  inches  from  the  anus,  can  be  reached  by  the  tip 
of  the  finger  on  rectal  examination,  but,  as  they  cannot  be 
completely  examined,  care  must  be  taken  not  to  mistake  them 
for  a  malignant  tumour.  The  plicae  transversales  recti  can 
easily  be  seen  on  examination  with  the  sigmoidoscope  when 
the  bowel  has  been  artificially  distended,  but  even  then  they 
may  tend  to  obstruct  the  passage  of  the  instrument. 

Posteriorly,  the  upper  two-thirds  of  the  rectum  is  in  contact 
with  the  sacrum  and  coccyx  in  the  median  plane,  and,  on  each 
side,  overlaps  the  piriformis  muscle  and  the  nerves  of  the  sacral 
plexus,  from  which,  however,  it  is  separated  by  the  parietal 
pelvic  fascia  and  its  own  covering  of  visceral  pelvic  fascia. 
When  loaded,  the  rectum  may  exert  pressure  on  the  nerves, 
especially  of  the  left  side,  and  produce  the  painful  symptoms 


THE  PELVIS  369 

of  sciatica.  The  lower  third  of  the  rectum  rests  on  the  pelvic 
floor  (p.  356)  and  is  surrounded  by  the  rectal  layer  of  the  visceral 
pelvic  fascia. 

The  hypogastric  (internal  iliac)  vessels,,  and  lymph  glands 
and  the  ureters  are  related  to  the  sides  of  the  rectum,  but  the 
latter  are  only  in  contact  with  its  wall  when  the  gut  is  con- 
siderably distended. 

Structure  of  the  Rectum. — The  submucous  coat  consists  of  very  loose 
areolar  tissue,  and,  as  a  result,  the  mucous  coat  may  become  prolapsed  through 
the  anus,  following  violent  straining. 

The  circular  muscular  coat  forms  a  complete  covering  for  the  gut  but 
the  longitudinal  coat  is  arranged  in  two  broad  bands,  which  lie  one  on  its 
anterior  and  the  other  on  its  posterior  surface.  The  shortness  of  these  bands, 
relative  to  the  length  of  the  mucous  and  circular  muscular  coats,  accounts  for 
the  production  of  the  lateral  flexures  of  the  rectum. 

The  Anal  Canal,  which  is  about  one  and  a  half  inches  long, 
passes  downwards  and  backwards  from  the  rectal  ampulla  to  the 
anus.  Except  during  defaecation,  its  walls  are  kept  in  apposition 
by  the  action  of  the  levatores  ani  and  sphincter  muscles.  The 
sides  of  the  anal  canal  are  in  relation  to  the  elastic  pads  of  fat 
which  occupy  the  ischio-rectal  fossae  (p.  373).  Anteriorly,  the 
anal  canal  is  related  to  the  urogenital  diaphragm,  the 
membranous  part  of  the  urethra  and  the  bulb  of  the  penis 
(Fig.  115).  The  surgeon  takes  advantage  of  this  relation  when 
he  is  negotiating  a  bougie  through  a  difficult  stricture  of  the 
urethra.  By  inserting  the  forefinger  of  his  left  hand  into  the 
rectal  ampulla,  he  can  control  the  point  of  the  instrument  and 
can  recognise  at  once  if  it  is  making  a  "  false  passage."  Further, 
in  supra-pubic  prostatectomy,  the  enucleating  finger  of  the 
right  hand  within  the  bladder  will  be  greatly  assisted  if  the 
surgeon  passes  his  left  forefinger  into  the  ampulla  of  the  rectum. 

The  recto-urethralis  muscle  extends  from  the  anterior  surface 
of  the  upper  end  of  the  anal  canal  to  the  superior  fascia  of  the 
urogenital  diaphragm.  When  it  has  been  cut  transversely, 
the  finger  can  be  inserted  into  a  loose  cellular  interval  which 
lies  between  the  rectum  and  the  prostate,  and  these  two  viscera 
can  then  be  easily  separated.  Section  of  the  recto-urethralis 
is  an  important  step  in  the  operations  of  prostatectomy  and 
excision  of  the  rectum  by  the  perineal  route  (p.  379). 

The  muscular  coat  of  the  anal  canal  is  very  strongly 
developed.  The  circular  fibres  of  the  rectum  are  continued 
downwards  to  form  the  internal  sphincter,  which  clothes  the 
upper  two-thirds  of  the  canal.  The  levatores  ani  lie  external 

24 


370  THE  ABDOMEN  AND   PELVIS 

to  the  internal  sphincter  and  some  of  their  fibres  are  prolonged 
downwards  in  the  wall  of  the  anal  canal.  The  external  sphincter 
lies  very  superficially,  and  is  attached  to  the  tip  of  the  coccyx 
behind  and  to  the  central  point  of  the  perineum  in  front. 

The  submucous  coat  of  the  anal  canal  is  very  lax  and 
contains  tributaries  of  the  haemorrhoidal  veins. 

The  mucous  coat  of  the  anal  canal  is  loosely  attached  to 
the  muscular  wall  and,  in  its  upper  part,  is  thrown  into  a  number 
of  vertical  folds,  termed  the  rectal  columns  (of  Morgagni).  These 
are  united  at  their  lower  ends  by  small  semilunar  folds,  which 
are  termed  the  anal  valves.  Ball  suggests  that  anal  fissure  is 
produced  by  the  tearing  downwards  of  one  of  the  anal  valves 
by  a  scybalous  mass. 

The  line  formed  by  the  anal  valves,  sometimes  termed 
the  pectinate  line,  marks  the  junction  between  the  columnar 
epithelium  of  the  intestinal  canal  and  the  scaly  epithelium  of 
the  skin,  and  therefore  indicates  the  site  of  the  embryonic  anal 
membrane  (p.  380). 

Blood-supply  of  the  Rectum  and  Anal  Canal. — (i)  The  superior 
hfzmorrhoidal  artery  (p.  341)  descends  in  the  root  of  the  pelvic  meso-colon 
and  divides  into  right  and  left  branches,  which  run  downwards  on  the  muscular 
coat  of  the  rectum.  They  give  off  numerous  branches,  which  pierce  the 
muscular  coat  and  supply  the  mucous  membrane  of  the  rectum  and  the  upper 
part  of  the  anal  canal,  anastomosing  freely  with  one  another  and  with  the 
inferior  and  middle  hsemorrhoidal  arteries. 

(2)  The  middle  h&morrhoidal  arteries  arise  from  the  hypogastric  arteries 
and  are  mainly  distributed  to  the  muscular  coat  of  the  'rectum.    As  they 
approach  the  gut  they  are  embedded  in  cellular  tissue,  which  offers  some 
resistance  when  the  surgeon  endeavours  to  drag  down  the  rectum  in  the 
operation  of  excision  (p.  382).    This  cellular  tissue  is  termed  by  Ball  the 
lateral  ligament  of  the  rectum. 

(3)  The  inferior  hcemorrhoidal  arteries  arise,  on  each  side,  from  the  internal 
pudendal  in  Alcock's  canal  (p.  373)  and  run  downwards  and  medially  across 
the  ischio-rectal  fossae  to  reach  the  sides  of  the  anal  canal.    They  are  dis- 
tributed to  the  muscular  wall  of  the  anal  canal  and  to  the  lower  part  of  its 
mucous  coat. 

(4)  The  middle  sacral  artery  arises  from  the  abdominal  aorta  near  its 
termination  and  runs  downwards  in  the  median  plane  on  the  anterior  surface 
of  the  sacrum.    It  supplies  a  few  twigs  to  the  muscular  coat  of  the  rectum. 

Veins  of  the  Rectum  and  Anal  Canal. — The  internal  hcemorrkoidal 
plexus  lies  in  the  submucous  tissue  of  the  anal  canal,  and  by  its  means  the 
superior,  middle,  and  inferior  hsemorrhoidal  veins  communicate  with  one 
another. 

The  superior  hezmorrhoidal  veins  arise  from  the  upper  end  of  the  plexus 
and  pass  upwards  in  the  submucous  coat  of  the  rectum.  About  the  middle 
of  the  rectum  they  pierce  the  muscular  coat  and  unite  to  form  a  common 
trunk,  which  ascends  in  the  pelvic  mesocolon  and  ultimately  becomes  the 
inferior  mesenteric  vein  (p.  321). 

The  middle  hcemorrhoidal  veins  also  arise  in  the  internal  haemorrhoidal 


THE  PELVIS  371 

plexus  and  pierce  the  muscular  coat  of  the  anal  canal.  They  run  backwards 
on  the  upper  surface  of  the  levator  ani  and  join  the  hypogastric  (internal 
iliac)  vein. 

The  inferior  hcemorrhoidal  veins  join  the  internal  pudendal  vein. 

The  anal  veins  are  arranged  radially  around  the  margin  of 
the.  anus.  They  communicate  with  the  internal  haemorrhoidal 
plexus  and  also  with  the  inferior  haemorrhoidal  veins.  Excessive 
straining  during  the  passage  of  large  scybala  may  lead  to  rupture 
of  one  of  the  anal  veins,  and  the  extravasated  blood  gives  rise 
to  a  small  swelling  at  the  muco-cutaneous  junction,  which  is 
termed  an  external  h&morrhoid. 

Varicosity  of  the  veins  of  the  internal  haemorrhoidal  plexus 
constitutes  the  condition  known  as  internal  hemorrhoids.  This 
may  be  brought  about  by  portal  obstruction,  whether  hepatic 
or  cardiac  in  origin,  since  the  portal  and  systemic  circulations 
communicate  in  the  internal  hsemorrhoidal  plexus  (p.  311). 
Further,  the  course  taken  by  the  superior  hsemorrhoidal  veins 
exposes  them  to  marked  obstruction  during  contraction  of  the 
muscular  coat  of  the  rectum  and  the  downward  passage  of 
faeces.  This  obstruction,  together  with  the  absence  of  venous 
valves,  acts  as  a  predisposing  cause  of  the  condition.  Internal 
haemorrhoids  may  become  prolapsed  through  the  anus  with 
each  evacuation  of  the  bowels  or  they  may  even  protrude  in 
the  erect  posture.  Their  constriction  by  the  external  sphincter 
gives  rise  to  an  acute  attack  of  "  piles,"  and  may  lead  to  areas 
of  sloughing  or  actual  gangrene. 

Bleeding  from  internal  haemorrhoids  is  venous  in  nature  and 
irregular  in  occurrence.  On  the  other  hand,  bleeding  from  a 
malignant  tumour  of  the  rectum  is  arterial  in  nature  and  occurs 
with  each  act  of  defaecation. 

In  the  operation  for  internal  haemorrhoids,  the  clamps  or 
forceps  should  be  applied  parallel  to  the  course  of  the  vessels, 
i.e.  in  the  long  axis  of  the  bowel,  and  special  care  should  be 
taken  to  make  sure  that  the  vessels  at  the  base  of  the  pile  are 
secured.  If  this  is  not  done,  considerable  haemorrhage  may 
occur  into  the  rectum  with  no  outward  sign  until  an  enormous 
blood-clot  is  passed  or  the  condition  of  the  pulseattraets  attention. 

The  Nerve -Supply  of  the  Rectum  and  Anal  Canal  is 
mainly  derived  from  S.  2,  3,  and  4,  through  the  sympathetic 
system.  The  nerves  which  supply  the  internal  trigone  of 
the  bladder  and  the  sphincter  vesicae  internus  are  derived 
from  the  same  source  (p.  362).  It  is  not  surprising  to  find 


372  THE  ABDOMEN  AND  PELVIS 

that  interference  with  the  rectum  or  anal  canal  produces 
reflex  results  in  the  bladder.  For  example,  retention  of  urine, 
due  to  spasm  of  the  sphincter  vesicse  internus,  may  follow 
operations  on  the  anus  or  rectum.  A  similar  result  may  be 
brought  about  by  irritation  of  the  cutaneous  nerves  of  the 
perineum  (S.  2,  3,  and  4),  e.g.  following  a  long  cycle  ride. 

Cutaneous  branches  are  supplied  by  S.  2  and  3  to  the  back 
of  the  thigh  and  leg  (p.  418),  and  may  be  the  site  of  referred 
pain  in  irritative  or  inflammatory  conditions  of  the  rectum  or 
pelvic  colon. 

The  lower  part  of  the  anal  canal,  which  is  ectodermal  in 
origin  (p.  381),  receives  its  nerve -supply  from  the  inferior 
haemorrhoidal  nerve. 

The  Lymph  Vessels  of  the  rectum  and  anal  canal,  above 
the  pectinate  line,  drain  into  lymph  glands  which  lie  on  the 
posterior  surface  of  the  rectum  and  their  efferents  ascend  along 
the  superior  hsemorrhoidal  artery  to  end  in  the  sacral  and 
lumbar  lymph  glands. 

From  the  lower  part  of  the  anal  canal,  the  lymph  vessels 
pass  to  the  subinguinal  lymph  glands  (p.  400).  They  reach  their 
destination  by  two  paths ;  some  run  antero-laterally  across 
the  urogenital  triangle,  and  the  others  run  postero-laterally 
round  the  lateral  aspect  of  the  thigh  at  about  the  level  of  the 
greater  trochanter.  From  the  inguinal  group,  efferents  pass 
through  the  femoral  (crural)  ring  to  join  the  external  iliac  lymph 
glands. 

Examination  of  the  Rectum  and  Anal  Canal. — After 
passing  through  the  anus,  the  finger  is  at  once  grasped  by  the 
external  sphincter,  but  may  be  gently  advanced  upwards  and 
forwards  for  about  one  and  a  half  inches,  until  it  slips  past 
the  internal  sphincter  and  enters  the  rectal  ampulla.  If  the 
anus  is  found  to  be  tightly  contracted  and  very  tender,  anal 
fissure  may  be  suspected,  and  further  examination  should  be 
conducted  under  an  anaesthetic. 

Through  the  lowest  part  of  the  anterior  wall  of  the  rectal 
ampulla  the  bulbo-urethral  glands  (of  Cowper)  can  be  felt,  when 
they  are  inflamed  and  enlarged.  At  a  slightly  higher  level, 
the  posterior  surface  of  the  prostate  can  be  examined.  The 
seminal  vesicles,  lying  on  the  posterior  surface  of  the  bladder, 
can  be  recognised,  when  diseased,  as  nodular  projections  im- 
mediately above  the  prostate.  About  three  inches  from  the 
anus,  which  is  the  average  limit  of  reach,  the  finger-tip  is  in 


THE  PERINEUM  373 

contact  with  the  rectal  wall  just  below  the  line  of  peritoneal 
reflection. 

If  the  finger  is  rotated  laterally,  the  medial  aspect  of  the 
pelvic  wall  may  be  examined,  and,  posterp-laterally,  the  hypo- 
gastric  (internal  iliac)  lymph  glands  can  be  made  out  when 
they  are  enlarged. 

With  the  pulp  of  the  finger  directed  backwards,  the  lowest 
plica  transversal-is  recti  (rectal  valve)  may  be  felt,  and  enlarged 
lymph  glands  on  the  anterior  surface  of  the  sacrum  can  be 
recognised  by  pressing  them  against  the  bone.  When  the 
patient  is  told  to  strain,  the  part  of  the  bowel  which  lies  just 
out  of  reach  in  the  passive  condition  can  be  "  threaded  "  on 
the  finger  and  examined. 

In  the  "  ballooned  "  condition  of  the  rectum,  the  walls  of 
the  gut  cannot  be  made  out  after  the  finger  has  passed  through 
the  internal  sphincter. 

In  the  female,  the  os  uteri  can  be  palpated  through  the 
anterior  wall  of  the  rectum,  and  the  uterus  itself  may  be  felt 
when  retroflexed. 


THE  PERINEUM. 

The  Ischio-Rectal  Fossa  lies  between  the  lower  part  of 
the  obturator  internus  and  the  levator  ani.  Posteriorly,  it  is 
limited  by  the  glutseus  maximus  and  the  sacro-tuberous  ligament; 
anteriorly,  it  extends  forwards  to  the  urogenital  diaphragm. 
Above,  it  is  shut  off  from  the  pelvis  by  the  attachment  of  the 
levator  ani  to  the  parietal  pelvic  fascia  (Fig.  114).  The  sloping 
medial  wall  of  the  fossa  is  formed  by  the  levator  ani  as  it  clothes 
the  anal  canal  and  the  lower  part  of  the  rectum. 

After  leaving  the  gluteal  region  (p.  417),  the  internal  pudendal 
vessels  enter  Alcock's  canal,  which  lies  in  the  fascia  on  the 
lateral  wall  of  the  ischio-rectal  fossa.  They  give  off  the  inferior 
hsemorrhoidal  vessels,  which  pass  downwards  and  medially 
across  the  fossa  to  supply  the  anal  canal.  The  vessels  are 
accompanied  by  the  inferior  hsemorrhoidal  nerve,  which  arises 
from  the  pudendal  and  terminates  in  the  external  sphincter. 

Ischio  -  rectal  abscesses  originating  in  connection  with 
some  small  ulcer,  laceration  of  the  rectal  sinuses,  etc.,  may 
rupture  through  the  skin  and  give  rise  to  an  external  sinus  ;  or 

24  a 


374 


THE   ABDOMEN   AND  PELVIS 


they  may  rupture  into  the  anal  canal,,  in  which  case  an  internal 
sinus  is  formed.  The  orifice  of  an  internal  sinus  is  generally 
found  at  the  pectinate  line  (p.  370),  i.e.  the  track  of  the  sinus 
lies  below  the  level  of  the  levator  ani  and  longitudinal  muscular 
coat  of  the  gut.  An  ischio-rectal  abscess  may  rupture  in  both 
directions  and  so  give  rise  to  a  complete  fistula.  As  the  whole 
fistula  lies  below  the  internal  sphincter,  it  is  only  necessary  to 
divide  the  external  sphincter,  the  movements  of  which  tend  to 
keep  the  fistula  open.  This  should  be  carried  out  radially  from 
the  anal  margin,  i.e.  at  right  angles  to  its  fibres,  and  in  one  place 


Bladder 


Recto-vesi 
fascia 


Anal  canal 


Obturator  internus 

Levator  ani,  clothed  on 

medial  side  by  rectal 

fascia,  and  on  lateral  side 

by  lower  fascia  of  pelvic 

diaphragm 

Alcock's  canal,  con-  „--" 
taining  pudendal 
vessels  and  nerve 

FiG.  114. — Diagram  of  the  Endo-pelvic  Fascia.     The  pelvis  is  divided  in  a 
frontal  plane  and  the  pelvic  fascia  is  represented  in  red. 

only,  otherwise  the  muscle  may  fail  to  unite.  In  the  examination 
of  a  case  of  fistula  in  ano,  it  is  advisable  to  pass  a  probe  into 
the  fistula  before  inserting  the  finger  into  the  anal  canal,  as 
this  process  may  induce  spasm  of  the  external  sphincter  and 
so  make  the  passage  of  a  probe  a  matter  of  greater  difficulty. 
Sometimes  the  mucous  membrane  is  undermined  for  some 
distance  above  the  internal  opening  of  the  fistula,  and  the 
point  of  the  probe  may  be  felt  separated  from  the  finger  by 
the  mucous  coat  alone. 

Abscesses  arising  above  the  levator  ani,  either  in  connection 
with  the  pelvic  organs  or  diseased  bone,  sometimes  pierce  the 
muscle  and  enter  the  ischio-rectal  fossa  from  above. 

The  Pudendal  Nerve  arises  from  the  sacral  plexus  (S.  2,  3, 


THE   PERINEUM 


375 


and  4);  and  accompanies  the  internal  pudenda!  vessels  through 
the  greater  sciatic  foramen  (p.  417).  It  then  passes  downwards 
on  the  dorsal  surface  of  the  sacro-spinous  (small  sacro-sciatic) 


Parietal 

peritoneum 

Fascia 

transversalis 

Fascia  of  Scarp 


ascia  of  Camper 

Bladder  I  H 
II 
If 
l| 

Pubo-prostatic       /' 
ligament 

Frost 

Deep  dorsal 
vein  of  penis 


Urethra 

!ulb  of  corpus 

cavernosum 

urethrse 

Bulbo-caver- 

nosus  muscle 


Prepuce 

Fossa 
navicularis 


Parietal  pelvic 
fascia 


Sacro-genital 

fold 

Ductus  defereri 

Recto-vesical 

fascia 

Ejaculatory 

duct 

Upper  fascia  of 

urogenital 

diaphragm 

Lower  fascia  ol 

urogenital 

diaphragm 

Anal  canal 


Fascia  of  Colles 


FIG.  115. — Diagram  of  Median  Section  through  Male  Pelvis,  showing  the 
arrangement  of  the  Peritoneum,  the  Endopelvic  Fascia  and  the  Fascia 
of  Colles. 

ligament  and  enters  the  posterior  part  of  the  ischio-rectal  fossa 
through  the  lesser  sciatic  foramen.  In  Alcock's  canal,  it  gives 
off  the  inferior  hczmorrhoidal  and  divides  into  the  perineal  nerve 
and  the  dorsal  nerve  of  the  penis. 

24  6 


376  THE  ABDOMEN  AND  PELVIS 

The  Urogenital  Triangle  extends  from  the  pubic 
symphysis  to  the  central  point  of  the  perineum,  which  lies 
half  an  inch  anterior  to  the  anus,  and  it  is  limited  laterally  by 
the  pubic  arch. 

The  superficial  fascia  over  this  region  consists  of  two  strata. 
The  first  is  a  fatty  layer,  continuous  with  the  general  fatty 
covering  of  the  body.  The  second,  the  deeper  layer,  is  denser 
and  more  membranous  in  character.  Above,  it  is  continuous 
with  the  fascia  of  Scarpa  (p.  240),  which  is  continued  downwards 
from  the  abdomen  on  each  side  to  be  attached  to  the  fascia  lata 
of  the  thigh  just  distal  to  the  inguinal  (Poupart's)  ligament. 
Between  the  two  pubic  tubercles,  the  fascia  of  Scarpa  is  carried 
down  over  the  urogenital  triangle,  where  it  is  termed  the  fascia 
of  Colles.  The  latter  encloses  the  penis,  as  in  the  finger  of  a 
glove,  clothes  the  scrotum,  and  finally  blends  with  the  base  of 
the  urogenital  diaphragm.  Laterally,  the  fascia  of  Colles  is 
attached  to  the  fascia  lata  of  the  thigh  from  the  pubic  tubercle 
downwards  and  medially  to  the  border  of  the  pubic  arch,  and 
then  along  the  latter  to  the  tuber  ischii. 

The  Superficial  Perineal  Pouch  is  a  space  which  is  bounded 
in  front  by  the  fascia  of  Colles,  and  behind  by  the  urogenital 
diaphragm.  It  is  closed  inferiorly  by  the  union  of  its  two  walls 
and  laterally  by  their  attachments  to  the  pubic  arch .  Superiorly, 
however,  it  communicates  freely  with  the  cellular  interval 
between  the  fascia  of  Scarpa  and  the  anterior  wall  of  the  rectus 
sheath.  The  superficial  perineal  pouch  contains  the  structures 
which  form  the  root  of  the  penis  and  the  muscles  which  cover 
them  (p.  377).  It  also  contains  the  whole  of  the  cavernous 
(spongy)  portion  of  the  urethra,  and  rupture  of  this  portion  of 
the  urethra,  whether  from  trauma  or  following  stricture,  leads 
to  extravasation  of  urine  into  the  pouch.  This  first  affects  the 
lowest  part  of  the  pouch,  viz.  between  the  neck  of  the  scrotum 
and  the  base  of  the  urogenital  diaphragm,  and  then  passes 
forwards  and  distends  the  scrotum  (Fig.  115).  The  loose  cellular 
tissue  of  the  penis  next  becomes  infiltrated,  and  the  "  ram's 
horn  penis "  is  produced.  Lastly,  the  extra vasated  urine 
passes  upwards  on  to  the  anterior  abdominal  wall  spreading 
laterally  behind  the  fascia  of  Scarpa,  and  the  attachment  of  the 
latter  to  the  fascia  lata  prevents  its  downward  spread  into  the 
thigh. 

The  root  of  the  penis  consists  of  the  bulb  and  the  two  crura.    The 
bulb  is  placed  in  the  median  plane  and  is  closely  attached  to  the  inferior  fascia 


THE   PERINEUM 


377 


of  the  urogenital  diaphragm  (anterior  layer  of  triangular  ligament).  It  is 
traversed  by  the  urethra  and  its  surface  is  completely  covered  by  the  bulbo- 
cavernosus  (ejaculator  urincv)  muscle,  which  serves  to  eject  the  last  drops  of 
urine  or  semen.  The  cms  penis  is  firmly  attached  to  the  margin  of  the  pubic 
arch  and  is  covered  by  the  ischio-cavernosus  (erector,  penis}  muscle.  The  two 
crura  converge  anteriorly  and  lie  side  by  side  on  the  dorsum  of  the  body  of  the 
penis,  where  they  are  termed  the  corpora  cavernosa.  The  bulb  is  continued 
forwards  as  the  corpus  cavernosum  urethrae  (corpus  spongiosum),  which  forms 
the  ventral  part  of  the  body  of  the  penis. 

The  superficial  transverse  perineal  muscle  lies  in  the  most  posterior  part 
of  the  superficial  perineal  pouch  (Fig.  115).  It  cannot  be  exposed  without 
incising  the  fascia  of  Colles,  and  it  forms  an  important  landmark  in  perineal 
surgery. 


FIG.    116. — The  Segmental  Supply  of  the  Skin  in  the  Perineum. 

Superficial  Perineal  Nerves. — (i)  The  posterior  scrotal  nerves,  two 
in  number  on  each  side,  arise  from  the  pudendal  (S.  2,  3,  and  4)  and  supply 
the  skin  over  the  urogenital  triangle  and  the  scrotum. 

(2)  The  long  perineal  branch  (long  pudendal)  of  the  posterior  cutaneous 
nerve  of  the  thigh  (S.  i,  2,  and  3)  assists  in  the  supply  of  the  same  areas. 

(3)  The  dorsal  nerve  of  the  penis  arises  from  the  pudendal  (S.  2,  3,  and  4) 
and  runs  along  the  dorsum  of  the  penis.     It  ends  by  supplying  the  glans. 

(4)  The  perforating  cutaneous  nerve  (S.  2  and  3)  supplies  the  skin  in  the 
neighbourhood  of  the  coccyx. 

(5)  The  perineal  branch  of  S.  4  supplies  the  skin  round  the  anus. 

(6)  The  inferior  htzmorrhoidal  nerve  (p.  375)  helps  the  perineal  branch  of 
S.  4  to  supply  the  skin  round  the  anus. 

The  superficial  nerves  of  the  perineum  all  spring  from  the 
anterior  rami  of  the  sacral  nerves.  Pain  may  be  referred  to 


378  THE  ABDOMEN  AND  PELVIS 

this  region  in  irritative  conditions  of  those  viscera  which  receive 
their  nerve-supply  from  the  same  source,  e.g.  bladder,  rectum, 
seminal  vesicles,  etc.  It  has  already  been  pointed  out  (p.  372) 
that  irritation  of  the  perineal  nerves  may  reflexly  affect  the 
viscera  mentioned. 

The  Urogenital  Diaphragm  separates  the  perineum  from 
the  pelvis  anteriorly.  It  is  formed  by  the  sphincter  urethrse 
and  the  deep  transverse  perineal  muscles,  which  are  enclosed 
between  two  layers  of  fascia.  The  two  fascial  layers  blend 
with  one  another  and  with  the  fascia  of  Colles  inferiorly,  and 
they  are  attached  on  each  side  to  the  margin  of  the  pubic  arch. 
The  superior  fascia  (deep  layer  of  triangular  ligament)  consists 
of  parietal  pelvic  fascia  (p.  356),  while  the  inferior  fascia 
(superficial  layer  of  triangular  ligament)  forms  the  postero- 
superior  wall  of  the  superficial  perineal  pouch.  The  space 
between  the  two  layers  is  completely  closed  and  is  termed  the 
deep  perineal  pouch.  It  contains  (i)  the  membranous  portion 
of  the  urethra  and  its  sphincter  muscle,  (2)  the  deep  transverse 
perineal  muscle  and  the  bulbo-urethral  glands  (of  Cowper), 
(3)  the  artery  to  the  bulb,  and  (4)  the  internal  pudendal  vessels 
and  the  dorsal  nerve  of  the  penis. 

Rupture  of  the  membranous  portion  of  the  urethra  leads  to 
extravasation  of  urine  into  the  deep  perineal  pouch,  and  the 
extravasated  urine  can  only  find  an  exit  from  this  space  by 
bursting  through  either  the  anterior  or  the  posterior  wall  of  the 
pouch.  In  the  first  case,  the  urine  then  passes  into  the  superficial 
perineal  pouch,  and  its  subsequent  course  is  described  on  p.  376. 
In  the  second  case  it  enters  the  interval  which  lies  immediately 
below  the  pubo-prostatic  ligaments  (Fig.  115);  and  bursts 
through  between  them,  gaining  the  space  of  Retzius.  It  then 
ascends  the  anterior  abdominal  wall  between  the  trans versalis 
fascia  and  the  parietal  peritoneum.  Extravasated  urine  will 
also  be  found  in  this  situation  after  rupture  of  the  prostatic 
urethra,  and  after  extra-peritoneal  rupture  of  the  bladder. 

The  Internal  Pudendal  Artery,  on  leaving  Alcock's  canal, 
pierces  the  base  of  the  urogenital  diaphragm  and  runs  forwards 
in  the  lateral  part  of  the  deep  perineal  pouch.  It  pierces  the 
inferior  fascia  of  the  diaphragm  under  cover  of  the  cms  penis 
and  ends  by  dividing  into  the  deep  artery  of  the  penis  (artery  to 
the  corpus  cavernosum}  and  the  dorsal  artery  of  the  penis.  Before 
it  enters  the  pouch,  it  gives  off  superficial  branches,  which  ramify 
in  the  superficial  pouch  and  supply  the  muscles  and  skin. 


THE  PERINEUM  379 

In  the  deep  perineal  pouch,  the  internal  pudendal  gives  off 
the  important  artery  to  the  bulb,  which  runs  medially  and  pierces 
the  inferior  fascia  of  the  urogenital  diaphragm  near  the  middle 
line  in  order  to  reach  the  bulb.  It  usually  lies  three-quarters 
of  an  inch  from  the  base  of  the  diaphragm.  In  the  old  operation 
of  lateral  lithotomy,  the  point  of  the  knife  was  entered  i£  inches 
in  front  of  the  anus  and  just  to  the  left  of  the  middle  line,  and 
was  carried  backwards  and  laterally  through  the  left  ischio- 
rectal  fossa  towards  a  point  midway  between  the  anus  and  the 
tuber  ischii.  In  this  way  the  whole  of  the  incision  lay  behind 
the  artery  to  the  bulb.  The  posterior  fibres  of  the  bulbo- 
cavernosus  and  the  superficial  transverse  perineal  muscle  and 
artery  were  divided  in  the  anterior  part  of  the  wound,  and  the 
urethra  was  reached  by  incising  the  inferior  fascia  of  the 
urogenital  diaphragm  and  the  sphincter  urethrae.  The  point 
of  the  knife  was  then  carried  along  the  grooved  staff  into  the 
bladder,  cutting  through  the  left  lobe  of  the  prostate  and  its 
sheath. 

Perineal  Prostatectomy. — In  this  operation  the  prostate 
is  approached  from  below  and  behind. 

An  incision,  convex  forwards,  is  made  between  the  ischial 
tuberosities,  and  the  skin  and  fasciae  are  reflected  until  the 
superficial  transverse  perineal  muscle  is  exposed  and  the  base 
of  the  urogenital  diaphragm  defined.  The  recto-urethralis 
muscle  is  then  exposed  and  divided  transversely.  The  fingers 
may  now  be  inserted  into  the  cellular  interval  between  the 
prostate  and  the  rectum  and  the  two  viscera  can  readily  be 
separated.  The  urethra  is  then  incised  at  the  apex  of  the 
prostate,  by  cutting  on  a  staff  with  a  median  groove.  The 
incision  should  not  be  more  than  a  third  of  an  inch  long  and 
should  not  injure  the  sphincter  urethrae.  The  staff  may  then 
be  withdrawn  and  Young's  prostatic  tractor  is  passed  into  the 
bladder  through  the  incision  in  the  urethra.  By  its  means, 
the  prostate  is  drawn  downwards  and  backwards  till  it  appears 
in  the  wound.  Its  sheath  is  then  incised  on  each  side,  and  the 
two  halves  of  the  prostate  are  removed  separately. 

This  operation  was  introduced  by  Young,  of  Baltimore,  with 
a  view  to  preserving  the  ejaculatory  ducts  and  the  prostatic 
urethra.  Further,  the  mucous  coat  of  the  bladder  is  not 
interfered  with,  and  perineal  drainage  is  obtained  through  the 
urethral  wound. 

Development  of  the  Genito-Urinary  Organs.— The  part  of  the  gut 


380  THE  ABDOMEN  AND   PELVIS 

which  lies  caudal  to  the  origin  of  the  allantois  (Fig.  89)  is  known  as  the 
cloaca,  and  it  becomes  subdivided  by  a  frontal  (coronal)  mesodermal  septum 
into  ventral  and  dorsal  portions.  The  ventral  portion  is  differentiated  into 
a  dilated  upper  part  which  forms  the  bladder,  and  a  narrower  lower  part 
which  is  termed  the  urogenital  sinus,  and  the  latter  receives  the  openings  of 
the  Wolffian  ducts.  The  dorsal  portion  of  the  cloaca  forms  the  rectum,  and, 
probably,  other  parts  of  the  large  intestine. 

Prior  to  this  subdivision,  the  ectoderm  and  entoderm  in  the  ventral  wall 
of  the  cloaca  are  in  direct  apposition — no  mesoderm  intervening — over  an 
area  which  is  termed  the  doacal  membrane.  In  the  adult,  this  corresponds 
roughly  to  the  area  between  the  symphysis  pubis  and  the  tip  of  the  coccyx. 
The  septum  which  subdivides  the  cloaca  reaches  the  cloacal  membrane  and 
divides  it  into  two  parts,  which  are  known  as  the  urogenital  and  anal  mem- 
branes, respectively.  About  the  eighth  week  of  foetal  life  the  urogenital 
membrane  breaks  down,  and  the  bladder  thus  acquires  an  opening  on  the 
surface  of  the  perineum. 

At  the  cephalic  end  of  the  cloacal  membrane,  the  ectoderm  becomes 
heaped  up  to  form  an  elevation,  which,  in  the  male,  becomes  the  phallus. 
Before  the  urogenital  membrane  breaks  down,  the  urogenital  sinus  extends 
forwards,  so  that  after  the  rupture  it  opens  not  only  on  the  perineum  but 
also  on  the  caudal  aspect  of  the  phallus.  As  the  latter  rapidly  increases  in 
the  male  to  form  the  penis,  the  opening  extends  forwards  and,  pari  passu, 
becomes  closed  posteriorly,  so  that  the  urethra,  which  is  thus  derived  from 
entoderm,  ultimately  opens  on  the  ventral  surface  of  the  penis  at  the  base 
of  the  glans.  At  a  later  stage,  the  urethra  extends  into  the  glans  and  the 
orifice  migrates  forwards  to  the  apex.  It  is  still  doubtful  whether  the  terminal 
part  of  the  urethra  is  ectodermal  or  entodermal  in  origin. 

In  the  female,  the  genital  eminence  forms  the  clitoris,  which  is  homologous 
with  the  glans  penis. 

Congenital  Anomalies. — (a)  Hypospadias.  The  simplest  variety  of 
hypospadias  is  due  to  persistence  of  the  orifice  at  the  base  of  the  glans  ;  the 
highest  degree  is  found  where  the  phallus  remains  diminutive,  and  the 
membranous  urethra  opens  on  the  surface  of  the  perineum.  Intermediate 
degrees  of  this  anomaly  may  occur. 

(b)  In  Epispadias,  the  urethra  opens  on  the  dorsal  surface  of  the  penis 
near  its  attachment  to  the  anterior  abdominal  wall.    This  abnormality  is 
due  to  rupture  of  the  urogenital  membrane  at  a  point  cephalic  to  the  genital 
eminence  instead  of  caudal  to  it. 

(c)  In  some  cases,   the  urogenital  membrane  is  more  extensive   than 
normal,  and  rupture  cephalic  to  the  genital  eminence  not  only  gives  rise  to 
epispadias  but  the  cleft  is  continued  forwards  and  complete  extroversion  of  the 
bladder  is  produced.      In  this  condition,  the  lower  part  of  the  anterior 
abdominal  wall  is  deficient  and  the  two  pubic  bones  fail  to  meet  one  another 
in  the  middle  line,  so  that  the  symphysis  is  absent.    The  posterior  wall  of  the 
bladder  is  exposed  on  the  surface  below  the  umbilicus  and  forms  a  somewhat 
triangular  red  area,  on  which  the  ureters  and  genital  ducts  open.    The 
margins  of  the  mucous  membrane  are  continuous  with  the  skin  of  the 
abdominal  wall.     Complete  extroversion  of  the  bladder  is  always  accompanied 
by  epispadias. 

The  Scrotum. — Two  lateral  swellings,  which  are  termed  the  labio-scrotal 
folds,  lie  one  on  each  side  of  the  genital  eminence.  As  they  grow  tailwards. 
they  pass  lateral  to  the  perineal  orifice  of  the  urogenital  sinus,  and  they  blend 
with  a  central  swelling  which  occupies  the  middle  line  in  front  of  the  anus. 
In  the  male,  the  scrotum  is  formed  by  this  central  swelling  and  the  caudal 
ends  of  the  labio-scrotal  folds.  In  the  female,  the  labio-scrotal  folds  persist 
in  their  entirety  and  constitute  the  labia  majora. 


THE  PERINEUM  381 

The  Urachus  is  a  fibrous  cord  which  extends  in  the  adult  from  the  apex 
of  the  bladder  to  the  umbilicus.  It  lies  between  the  fascia  transversalis 
and  the  parietal  peritoneum  and  represents  the  embryonic  connection  between 
the  cloaca  and  the  allantois,  after  the  formation  of  the  umbilical  cord  (p.  287). 
This  connection  normally  disappears  quite  early,  but  it  may  persist  and  give 
rise  to  cysts  or  umbilical  urinary  fistultz. 

Congenital  Anomalies  of  the  Rectum  and  Anal  Canal.— 

The  anal  membrane  (p.  380)  lies  at  the  bottom  of  a  surface 
depression,  which  is  termed  the  proctodceum.  During  the  third 
month;  the  anal  membrane  breaks  down  and  the  alimentary 
canal  opens  on  the  perineum.  The  upper  half  of  the  anal  canal 
is  entodermal  in  origin,  but  its  lower  half  is  derived  from  the 
ectoderm  lining  the  proctodaeum. 

Should  the  anal  membrane  fail  to  break  down,  the  condition 
of  imperforale  anus  results.  In  some  cases,  the  condition  is 
very  simple,  and  a  small  incision  through  the  anal  depression 
at  once  opens  the  lower  end  of  the  rectum.  In  other  cases, 
however,  the  rectum  ends  blindly  two  or  three  inches  or  more 
from  the  surface.  It  is  probable  that,  in  these  cases,  the 
mesoderm,  which  separates  the  urogenital  and  anal  membranes, 
has  invaded  the  latter  and,  by  rapid  proliferation,  has  widely 
separated  its  two  layers  from  one  another. 

Connections  of  the  rectum  with  the  bladder  or  prostatic 
urethra  are  due  to  failure  of  the  mesodermic  septum  to  effect 
a  complete  subdivision  of  the  cloaca  into  ventral,  urinary,  and 
dorsal,  intestinal  segments. 

In  Excision  of  the  Rectum,  the  method  adopted  depends 
entirely  on  the  extent  of  the  disease.  The  operation  which  is 
described  here  is  chosen  when  a  permanent  colostomy  has  been 
previously  established  ;  and  it  is  carried  out  with  the  patient 
in  the  exaggerated  lithotomy  position.  In  order  to  prevent 
any  leakage  during  the  subsequent  manipulations,  the  anus  is 
stitched  up  and  an  incision  is  made  through  the  skin  and  fascia 
around  it.  This  is  continued  backwards  in  the  median  plane 
up  over  the  coccyx  and  lower  part  of  the  sacrum,  if  considered 
necessary.  The  posterior  part  of  the  incision  is  deepened  and 
the  median  raphe  of  the  levatores  ani  is  split  as  far  back  as  the 
coccyx.  In  the  removal  of  the  coccyx,  which  constitutes  the 
next  step,  the  glutseus  maximus  must  be  separated  from  its 
dorsal  surface  and  the  attachments  of  the  coccygeus  and  the 
sacro-spinous  and  sacro-tuberous  ligaments  (small  and  great 
sacro-sciatic  ligaments)  to  its  sides  require  to  be  cut  through. 
The  bone  may  then  be  disarticulated  from  the  sacrum  or,  if 


382  THE  ABDOMEN  AND  PELVIS 

necessary,  the  lower  part  of  the  sacrum  may  be  removed,  but 
the  bone  must  be  divided  below  the  third  pair  of  sacral  foramina, 
otherwise  incontinence  of  urine  and  faces  will  result. 

The  middle  sacral  artery  (p.  370)  is  ligatured,  and  then,  by 
dissection  with  the  fingers,  the  levator  ani  is  separated  from 
the  rectum  on  each  side  and  the  visceral  layer  of  the  pelvic  fascia 
is  torn  through  as  it  passes  from  the  upper  surface  of  the  muscle 
on  to  the  gut.  In  the  region  of  the  rectal  ampulla,  the  fingers 
may  be  gradually  insinuated  round  the  bowel,  passing  between 
it  and  the  base  of  the  bladder  and  prostate.  One  blade  of  a 
pair  of  scissors  is  next  inserted  above  the  levator  ani  at  the 
point  where  the  median  incision  meets  the  incision  round  the 
anus,  and,  with  the  other  blade  in  the  circular  incision,  the 
wound  is  deepened  around  the  anal  canal.  In  this  process 
the  levatores  ani  are  divided  until  their  anterior  free  borders  are 
reached  on  the  antero-lateral  aspect  of  the  rectum.  Anteriorly, 
the  recto-urethralis  and  the  attachment  of  the  external  sphincter 
to  the  central  point  of  the  perineum  require  to  be  cut  through, 
and  the  former  must  be  divided  as  close  to  the  rectum  as  possible, 
in  order  to  avoid  injuring  the  membranous  part  of  the  urethra. 

As  a  result  of  this  step,  the  anal  canal  and  the  lower  two 
inches  of  the  rectum  can  be  dragged  downwards  and  a  further 
inch  can  be  freed,  with  the  fingers  and  with  scissors,  from  its 
anterior  peritoneal  covering. 

Some  difficulty  will  be  experienced  in  dragging  down  more 
of  the  rectum,  as  it  is  anchored  in  place  by  the  cellular  tissue 
in  which  the  middle  hsemorrhoidal  vessels  are  embedded.  These 
"  lateral  ligaments  "  having  been  clamped  and  divided,  the 
bowel  is  only  held  by  its  peritoneal  covering.  The  peritoneum  is 
incised  transversely,  close  to  the  rectum,  along  the  recto-vesical 
line  of  reflexion.  As  the  bowel  is  gradually  pulled  down,  the 
peritoneum  is  incised  along  each  side  and  the  branches  of  the 
superior  hsemorrhoidal  artery  are  secured  as  they  are  met  with. 

After  the  bowel  has  been  mobilised  for  some  distance  above 
the  diseased  area,  its  peritoneal  surface  is  stitched  to  the  cut 
recto-vesical  peritoneum.  Just  below  the  sutured  area,  the 
bowel  is  ligated  and  cut  through,  and  it  can  then  be  lifted  away. 
The  proximal  cut  end  may  be  surrounded  with  a  purse-string 
suture  and  invaginated,  the  usual  procedure  in  closure  of  the 
large  intestine. 

This  operation  produces  less  shock  than  some  of  the  more 
extensive  operations  which  provide  the  patient  with  a  new 


THE  PERINEUM  383 

rectum  and  anal  canal.  In  such  operations  the  pelvic  colon  is 
mobilised  (p.  343)  so  as  to  permit  of  its  being  stitched  to  the 
anus,  and,  at  the  same  time,  the  external  sphincter  is  preserved. 

The  Male  Urethra  is  about  nine  inches  long  from  its 
internal  orifice  at  the  neck  of  the  bladder  to  its  external  orifice 
on  the  glans  penis.  It  may  be  conveniently  divided  into  a 
posterior,  fixed  portion,  consisting  of  the  prostatic  and 
membranous  parts  and  the  part  within  the  bulb  and  an  anterior, 
movable  portion,  situated  in  the  corpus  cavernosum  urethrae 
(corpus  spongiosum). 

In  the  flaccid  condition  of  the  penis,  the  urethra  follows  an 
c/) -shaped  bend,  but  when  the  penis  is  drawn  upwards  towards 
the  abdomen,  its  course  becomes  J-shaped.  By  this  alteration, 
the  surgeon  is  enabled  to  pass  a  rigid  instrument  with  a  single 
curve  along  the  urethra  into  the  bladder. 

The  Prostatic  Part  of  the  Urethra  is  about  ij  inches 
in  length  and  is  embedded  in  the  prostate,  somewhat  nearer 
to  the  anterior  than  to  the  posterior  surface.  It  is  the  widest 
and  also  the  most  dilatable  part  of  the  urethra.  About  half 
an  inch  wide  at  its  mid-point,  it  narrows  slightly  at  each  end, 
but  it  may  be  dilated  so  as  to  permit  the  passage  of  the  finger 
into  the  bladder.  On  account  of  this  distensibility,  the  removal 
of  stones  from  the  bladder  was  at  one  time  carried  out  through 
the  prostatic  urethra. 

A  longitudinal  ridge,  termed  the  urethral  crest,  occupies  the 
floor  of  the  prostatic  urethra  in  nearly  its  whole  extent. 
Longitudinal  grooves  lie  one  on  each  side  of  the  crest ;  they  are 
termed  the  prostatic  sinuses  and  receive  the  prostatic  ducts. 
It  is  in  these  ducts  that  chronic  gonorrhceal  inflammation  may 
linger  in  posterior  urethritis.  Near  the  lower  end  of  the  crest, 
a  small  median  opening  leads  into  a  blind  diverticulum,  which 
passes  upwards  and  backwards  below  the  middle  lobe  of  the 
prostate.  This  is  termed  the  prostatic  utricle  (sinus  pocularis), 
and  near  its  orifice,  which  is  sometimes  large  enough  to  entangle 
the  point  of  a  fine  instrument,  the  prostatic  urethra  receives 
the  openings  of  the  ejaculatory  ducts.  Gonorrhceal  infection 
of  the  posterior  urethra  may  spread  into  the  ejaculatory  ducts 
and  involve  the  seminal  vesicles,  or  it  may  spread  along  the 
ductus  (vas)  deferens  and  give  rise  to  epididymitis. 

The  Membranous  Part  of  the  Urethra  is  narrower  than 
any  other  part  of  the  urethra  except  the  external  orifice.  It 
is  only  three-quarters  of  an  inch  long,  and  it  lies  between  the 


384  THE  ABDOMEN  AND  PELVIS 

two  fascial  layers  of  the  urogenital  diaphragm,  surrounded  by 
its  sphincter  muscle  (p.  378). 

The  bulbo-urethral  glands  (of  Cowper)  lie  infero-lateral  to  the 
membranous  urethra,  and  their  ducts  pierce  the  inferior  fascia 
of  the  diaphragm  (p.  378)  to  open  into  the  cavernous  urethra. 
These  glands  are  sometimes  involved  in  gonorrhceal  inflammation 
of  the  anterior  urethra,  and  they  may  give  rise  to  abscesses, 
which  can  be  recognised  on  rectal  examination.  The  pus 
should  be  evacuated  through  the  perineum. 

The  Cavernous  (Spongy)  Part  of  the  Urethra  is  about 
six  or  seven  inches  long  and  is  enclosed  in  the  bulb,  the  corpus 
cavernosum  (spongiosum)  urethras  and  the  glans  penis.  The 
external  orifice  on  the  glans  is  the  narrowest  part  of  the  canal, 
and  it  may  require  to  be  incised  to  permit  the  passage  of  bougies, 
which  will  then  readily  pass  along  the  remainder  of  the  urethra. 
Enlargement  of  the  external  urethral  orifice  should  be  carried 
out  by  cutting  from  within  outwards  towards  the  fraenulum. 

Immediately  within  the  external  orifice,  the  urethra  widens 
out  to  form  the  fossa  navicularis,  which  involves  the  roof  rather 
than  the  floor  of  the  canal.  Near  the  posterior  end  of  the  fossa 
a  fold  of  mucous  membrane  projects  downwards  from  the  roof 
and  may  temporarily  hinder  the  passage  of  an  instrument,  but, 
by  directing  the  point  of  the  instrument  towards  the  floor  of 
the  urethra,  this  slight  obstruction  is  easily  avoided. 

Behind  the  fossa  navicularis,  the  urethra  becomes  narrower, 
but  it  again  enlarges  when  it  reaches  the  bulb.  This  is  the 
most  dependent  part  of  the  fixed  urethra,  and,  on  this  account, 
is  the  commonest  site  of  chronic  gonorrhceal  inflammation,  and, 
consequently,  of  organic  stricture. 

Stricture  may  occur  at  any  point  in  the  cavernous  urethra. 
When  more  than  one  is  present,  the  first  should  be  dilated  to 
full  size  before  the  next  is  dealt  with.  If  this  is  not  done,  it 
may  be  impossible  to  determine  whether  a  bougie  is  obstructed 
by  a  deep  stricture  or  whether  its  shoulders  are  caught  in  the 
one  first  encountered. 

In  negotiating  a  difficult  stricture  in  the  bulb,  great  care 
and  gentleness  must  be  exercised  lest  a  false  passage  be  made. 
The  surgeon  stands  on  the  left  side  of  the  patient  and  manipulates 
the  handle  of  the  instrument  with  his  right  hand.  This  leaves 
his  left  hand  free,  and  the  left  forefinger,  if  inserted  into  the 
rectum,  may  be  of  great  assistance  in  guiding  the  point  of  the 
instrument,  thus  preventing  the  formation  of  a  false  passage. 


THE  PERINEUM  385 

The  passage  of  a  rigid  instrument.  No.  8  or  9,  along  a  healthy 
urethra  into  the  bladder  presents  no  difficulty,  if  its  point  is 
kept  in  contact  with  the  roof  of  the  urethra  after  the  fossa 
navicularis  has  been  traversed.  When  a  small  instrument  is 
used,  some  difficulty  may  be  experienced  in  passing  from  the 
bulb  into  the  membranous  urethra  as,  unless  the  point  is  kept 
along  the  roof  of  the  canal,  it  impinges  against  the  urogenital 
diaphragm  just  below  the  urethral  opening.  In  these  cases, 
the  instrument  should  be  withdrawn  for  a  short  distance  and 
then  the  handle  should  be  depressed  so  that  the  point  may  rise 
towards  the  orifice  in  the  diaphragm. 

The  Body  of  the  Penis  consists  of  the  two  corpora  cavernosa, 
which  lie  side  by  side  on  the  dorsum,  and  the  corpus  cavernosum 
urethra  (c.  spongiosum),  which  lies  in  the  groove  separating  the 
two  corpora  cavernosa  ventrally.  At  its  termination,  the 
corpus  cavernosum  urethrae  expands  into  a  conical  enlargement, 
termed  the  glans  penis,  which  projects  dorsally  and  laterally, 
so  as  to  cover  the  extremities  of  the  corpora  cavernosa. 

The  component  parts  of  the  penis  contain  numerous  venous 
spaces,  in  which  the  blood  may  be  retarded  by  the  contraction 
of  the  ischio-cavernosi  and  the  bulbo  -  cavernosus  (p.  377), 
leading  to  enlargement  of  the  organ.  In  conditions  of 
gonorrhceal  inflammation,  the  spaces  in  the  corpus  cavernosum 
urethrae,  being  already  rilled  with  serous  exudate,  fail  to  distend, 
when  the  corpora  cavernosa  are  undergoing  distension.  As  a 
result,  the  penile  erection  is  not  straight  but  is  curved,  owing 
to  the  inelastic  condition  of  the  corpus  cavernosum  urethrae. 
This  constitutes  the  condition  which  is  known  as  chordee. 

The  skin  of  the  penis  is  very  thin,  and  is  freely  movable  over 
the  body  of  the  organ.  At  the  extremity  of  the  penis  it  is 
folded  back  to  form  a  hoodlike  covering  for  the  glans.  This  is 
termed  the  prepuce  •  its  deep  surface  is  lined  by  modified  skin, 
which  is  reflected  on  to  the  glans  (i)  at  its  base,  the  corona 
glandis,  and  (2)  on  its  ventral  aspect,  where  it  forms  the  frenulum. 
The  modified  skin  covering  the  glans  is  firmly  adherent,  and 
contains  sebaceous  glands,  which  secrete  the  smegma.  The 
latter  collects  in  the  region  of  the  corona  glandis,  and  may 
sometimes  form  concretions. 

In  the  condition  of  Phimosis  there  is  a  long  narrow  prepuce, 
which  cannot  be  drawn  back  off  the  glans.  Adhesions  between 
the  deep  surface  of  the  prepuce  and  the  skin  surface  of  the  glans 
may  give  rise,  reflexly,  to  urinary  disturbances.  The  whole 

25 


386  THE  ABDOMEN  AND   PELVIS 

condition  may  be  relieved  by  circumcision.  In  this  operation 
the  prepuce  is  drawn  forwards  over  the  apex  of  glans  and 
removed.  When  adhesions  are  present  the  prepuce  itself 
cannot  be  drawn  forwards,,  and  the  skin  which  is  drawn  forwards 
is  derived  from  the  body  of  the  penis.  If  this  portion  is  cut 
away,  the  cut  proximal  end  at  once  retracts,  and  the  penis  may 
be  almost  completely  denuded,  while  the  prepuce  is  left  intact, 
i.e.  a  circular  strip  of  skin  is  removed  from  the  body  of  the 
penis. 

In  the  normal  case,  when  the  prepuce  is  cut  away,  the 
external  covering  of  skin  retracts,  but  the  deep  layer  remains  in 
contact  with  the  glans.  This  layer  may  be  slit  along  the  dorsal 
surface  with  scissors,  but  care  must  be  taken  not  to  insert  the 
point  of  the  lower  blade  into  the  external  urethral  orifice. 
Thereafter,  each  portion  of  the  deep  layer  of  the  prepuce  may 
be  stripped  from  the  glans  with  the  ringers,  and  a  layer  of  smegma 
is  usually  disclosed  around  the  corona. 

On  the  dorsal  surface  tributaries  of  the  dorsal  vein  and 
branches  of  the  dorsal  arteries  of  the  penis  will  require  to  be 
tied.  In  addition,  if  the  frenulum  is  divided,  the  little  artery 
which  runs  in  it  must  be  secured ;  it  is  a  branch  of  one  of  the 
arteries  to  the  bulb.  The  cut  edge  of  the  skin  is  then  stitched 
to  the  deep  layer  of  the  prepuce. 

The  condition  of  Paraphimosis  results  when  a  tight  prepuce 
is  drawn  backwards  off  the  glans  and  allowed  to  remain  as  a 
constricting  band  above  the  corona.  The  glans  becomes 
engorged  and  cedematous,  and  actual  gangrene  may  ensue, 
unless  the  prepuce  is  replaced.  This  may  be  carried  out  by 
exercising  steady  pressure  on  the  glans  with  the  thumbs  while 
traction  on  the  prepuce  is  maintained  by  the  encircling  fingers. 

The  Superficial  Dorsal  Vein  of  the  Penis  arises  on  the 
dorsum  just  behind  the  glans  by  the  union  of  small  tributaries 
from  the  glans  and  prepuce.  It  runs  backwards  in  the  middle 
line  immediately  under  the  skin  of  the  dorsum,  and  ends  by 
dividing  into  right  and  left  branches,  which  join  the  internal 
pudendal  veins. 

The  Deep  Dorsal  Vein  of  the  Penis  lies  on  a  deeper  plane. 
It  passes  into  the  pelvis  between  the  symphysis  pubis  and  the 
upper  edge  of  the  urogenital  diaphragm  (Fig.  115),  and  finally 
it  divides  into  right  and  left  branches,  which  join  the  pudendal 
(prostatic)  plexus  of  veins. 

Each  Dorsal  Artery  of  the  Penis  arises  from  the  internal 


THE  FEMALE  PELVIS  387 

pudendal  (p.  378),  and  runs  forwards  on  the  dorsal  surface  of 
the  corpus  cavernosum  ;  which  it  supplies. 

The  Dorsal  Nerve  of  the  Penis  (S.  2,  3,  4)  is  derived  from 
the  pudendal  (p.  374).  It  lies  lateral  to  the  dorsal  artery  and 
supplies  branches  to  the  skin  of  the  penis,  prepuce,  and  glans. 

The  superficial  and  the  deep  lymph  vessels  of  the  penis  end, 
respectively,  in  the  superficial  and  the  deep  subinguinal  lymph 
glands  (p.  400). 


THE  FEMALE  PELVIS. 

The  differences  between  the  male  and  female  generative 
organs  necessitate  a  somewhat  different  arrangement  of  the 
Pelvic  Peritoneum  in  the  female. 

On  leaving  the  anterior  surface  of  the  rectum,  the  peritoneum 
passes  forwards,  forming  the  floor  of  the  recto-uterine  fossa, 
and  reaches  the  posterior  aspect  of  the  vagina,  which  it  clothes 
in  its  upper  fifth.  From  the  posterior  surface  of  the  vagina 
the  peritoneum  passes  upwards  on  the  posterior  surface  of  the 
uterus  to  the  fundus.  It  then  descends  over  the  anterior  surface 
of  the  uterus,  but  at  about  one  inch  above  the  vagina  it  passes 
forwards  on  to  the  superior  surface  of  the  bladder,  forming  the 
floor  of  the  utero-vesical  fossa  (Fig.  117). 

The  Broad  Ligament  of  the  Uterus  is  a  somewhat 
triangular  sheet  of  peritoneum  which  extends  laterally  from 
the  lateral  border  of  the  uterus  to  the  pelvic  wall.  It  consists 
of  two  layers  which  become  continuous  with  one  another  at  the 
upper  free  border  of  the  ligament,  where  they  enclose  the 
uterine  (Fallopian)  tube.  Infero-laterally  the  two  layers  separate 
to  cover  the  floor  and  side-walls  of  the  pelvis.  The  plane  of  the 
broad  ligament  depends  partly  on  the  position  of  the  uterus. 
Normally  its  anterior  surface  is  directed  downwards  and  slightly 
forwards. 

Certain  parts  of  the  broad  ligament  receive  special  names, 
(i)  The  mesosalpinx  is  the  part  which  lies  immediately  below 
the  uterine  tube.  (2)  The  mesovarium  is  the  fold  which  passes 
from  the  posterior  layer  of  the  broad  ligament  to  enclose  the 
ovary.  It  contains  the  ovarian  vessels,  nerves,  and  lymphatics. 
(3)  The  suspensory  ligament  of  the  ovary  is  that  part  of  the  broad 
ligament  which  extends  between  the  upper  pole  of  the  ovary 
and  the  pelvic  wall.  Its  lateral  attachment  is  placed  a  little 


388 


THE  ABDOMEN  AND   PELVIS 


below  and  behind  the  abdominal  inguinal  ring  (p.  264).  The 
ovarian  vessels,  etc.,  traverse  the  suspensory  ligament  on  their 
way  to  the  mesovarium. 

The  Vagina,  which  is  about  three  inches  long,  is  directed 
upwards  and  backwards  and  lies  in  the  interval  between  the 


Ureter 
Obturator  fossa    •    Ovary 


Ovarian  vessels 
Obturator  fossa     ,' 


Folds  produced  by  nerve-cords 
Pararectal  fossa 


Paravesical  fossa 
Round  ligament 


Obliterated  umbilical 

artery 

[nf.  epigastric  artery    ;' 


Recto-uterine  pouch  of  Douglas 

Utero-sacral  fold 

FIG.  117.  — Median  Section  through  the  Female  Pelvis  to  show  the  disposition 
of  the  Peritoneum.      (Dixon  and  Birmingham.) 

urethra  and  bladder,  in  front,  and  the  anal  canal  and  rectum, 
behind.  Its  upper  half  lies  above  the  level  of  the  muscular 
floor  of  the  pelvis,  and  is  surrounded  by  the  visceral  pelvic  fascia. 
Its  lower  half  is  embraced  by  the  levatores  ani,  and  at  a  lower 
level,  by  the  bulbs  of  the  vestibule  (p.  397),  and  the  bulbo- 
cavernosus  (sphincter  vaginse)  muscle. 

Superiorly,  the  vagina  is  attached  around  the  cervix  uteri, 
which  projects  obliquely  downwards  and  backwards  into  the 


THE   FEMALE   PELVIS  389 

canal.    Around  the  cervix  there  is  a  shallow  groove,,  termed 
ihefornix,  which  is  deepest  posteriorly. 

Anteriorly,  the  lower  part  of  the  vagina  is  related  to  the 
urethra.  This  area  may  undergo  sloughing  from  continual 
pressure  during  parturition,  and  a  urethro-vaginal  fistula  may 
result.  Above  this  level,  the  vagina  is  related  to  the  posterior 
surface  of  the  bladder,  from  which  it  is  only  separated  by  some 
loose  cellular  tissue,  as  it  lies  entirely  below  the  peritoneum 
of  the  utero  -  vesical  fossa.  This  arrangement  is  of  great 
importance  to  the  surgeon,  as  it  permits  the  bladder  to  be  easily 
separated  from  the  cervix  and  vagina.  It  is  through  this  area, 
too,  that  malignant  diseases  of  the  cervix  may  spread  to  the 
bladder. 

Posteriorly,  the  vagina  is  related  to  the  anal  canal  and  rectum. 
In  its  lower  part  it  is  separated  from  the  anal  canal  by  a  fibro- 
muscular  mass  which  is  termed  the  perineal  body,  and  in  its 
upper  fifth  or  more  it  is  separated  from  the  rectum  by  the  lowest 
part  of  the  recto-uterine  fossa  and  the  viscera  which  it  contains. 

During  parturition  the  posterior  commissure  (p.  397)  may 
give  way,  and  the  laceration  may  involve  the  skin  and  superficial 
tissues  of  the  perineum  as  far  back  as  the  anus.  The  posterior 
wall  of  the  vagina  may  also  be  involved,  and  occasionally  the 
levator  ani,  and  the  sphincter  muscles  of  the  anal  canal  are 
affected.  Incontinence  of  faeces  only  occurs  when  the  internal 
sphincter  is  torn  through. 

Following  severe  lacerations  of  the  perineum  which  involve 
the  levator  ani,  the  posterior  vaginal  wall  may  become  prolapsed 
through  the  vulva.  This  condition  is  usually  accompanied 
by  a  dilatation  of  the  ampulla  of  the  rectum,  which  pouches 
forwards  into  the  relaxed  posterior  vaginal  wall,  constituting 
the  condition  known  as  a  rectocele.  A  strain  is  thus  placed  on 
the  anterior  wall  of  the  vagina,  and  it  in  turn  becomes  prolapsed, 
dragging  the  bladder  with  it  to  form  a  cystocele.  Lastly,  the 
uterus  itself  descends,  and  a  complete  prolapse  is  the  final  stage. 

In  the  operation  of  colporrhaphy,  which  is  undertaken  as  a 
remedial  measure,  oval  areas  of  mucous  membrane  are  removed 
in  the  long  axis  of  the  anterior  and  posterior  vaginal  walls, 
and  the  cut  edges  are  then  stitched  together,  thus  narrowing 
the  vagina.  In  removing  the  mucous  membrane  of  the  anterior 
vaginal  wall  and  in  stitching  the  cut  edges  together  subse- 
quently, great  care  must  be  taken  to  avoid  injuring  the 
bladder  and  urethra. 

25  a 


390  THE  ABDOMEN  AND  PELVIS 

The  Uterus  is  about  three  inches  long  and  two  inches 
broad,  and  in  shape  resembles  a  pear,  flattened  antero-posteriorly. 
At  the  upper  ends  of  its  lateral  borders  it  receives  the  uterine 
tubes,  and  the  part  of  the  organ  which  lies  above  this  level  is 
termed  thefundus.  This  part  of  the  uterus  is  normally  directed 
forwards,  and  is  completely  covered  by  the  peritoneum,  which 
is  firmly  adherent  to  it. 

The  body  of  the  uterus  lies  below  the  fundus,  and  is  separated 
from  the  cervix  by  a  slight  constriction,  termed  the  isthmus. 
It  is  completely  covered  by  peritoneum,  which  separates  it, 
anteriorly,  from  the  superior  surface  of  the  bladder,  and 
posteiiorly,  from  the  recto-uterine  fossa.  The  body  of  the 
uterus  is  the  common  site  for  fibroids,  which  may  grow  in  the 
subserous,  muscular,  or  submucous  coats. 

The  Cervix  Uteri  consists  of  a  supra-vaginal  and  a  vaginal 
portion.  The  supra-vaginal  portion  is  covered  by  peritoneum 
on  its  posterior  surface  only,  and  this  covering  is  very  loosely 
attached  to  the  subjacent  muscular  coat.  Anteriorly,  the 
supra-vaginal  portion  of  the  cervix  is  related  to  the  bladder, 
from  which  it  is  separated  by  some  cellular  tissue  (p.  395). 

The  vaginal  portion  of  the  cervix  projects  downwards  and 
backwards  into  the  antero-superior  part  of  the  vagina,  and 
receives  a  covering  of  squamous  epithelium  similar  to  that 
which  lines  the  vagina. 

The  cervix  is  traversed  by  the  cervical  canal,  which 
communicates  with  the~cavity  of  the  uterus,  above,  through 
the  internal  orifice  and  with  the  vagina,  below,  through  the 
external  orifice.  In  nulliparse  the  external  orifice  of  the  uterus 
is  a  circular  depression,  and,  owing  to  the  line  of  axis  of  the 
cervix,  is  directed  against  the  posterior  vaginal  wall.  In 
multipart  the  orifice  becomes  an  irregularly  transverse  slit, 
with  somewhat  everted  anterior  and  posterior  lips.  The  cervical 
canal  readily  admits  a  sound  4  mm.  in  diameter.  Should  it 
fail  to  do  so,  the  condition  of  stenosis  is  present.  Stenosis  of 
the  cervix  obstructs  the  menstrual  flow,  and  gives  rise  to 
dysmenorrhcea,  which  is  most  marked  at  the  commencement 
of  the  period. 

Position  of  the  Uterus. — The  long  axis  of  the  uterus  is 
normally  directed  downwards  and  backwards,  and  this 
arrangement -is  described  as  anteversion  of  the  organ.  But  in 
addition  to  being  anteverted,  the  normal  uterus  is  bent  forwards 
on  itself  at  the  junction  of  the  body  with  the  cervix,  and  this 


THE  FEMALE  PELVIS    -  391 

condition  is  termed  anteflexion.  The  position  of  the  uterus 
varies  somewhat  with  the  condition  of  the  bladder,  but  the 
organ  is  prevented  from  becoming  retroflexed  and  retroverted 
by  two  ligaments  on  each  side. 

The  round  ligament  is  a  fibro  -  muscular  band,  which  is 
attached  to  the  uterus  just  below  the  uterine  tube.  It  passes 
laterally  in  the  broad  ligament,  and  projects  slightly  from  its 
anterior  layer.  On  leaving  the  broad  ligament,  the  round 
ligament  of  the  uterus  enters  the  abdominal  inguinal  ring, 
traverses  the  inguinal  canal,  and  emerges  from  the  subcutaneous 
inguinal  ring  to  be  attached  to  the  skin  and  subcutaneous  tissue 
of  the  labium  majus  (p.  396).  Its  relations  at  the  abdominal 
inguinal  ring  and  in  the  canal  are  precisely  the  same  as  those 
already  described  for  the  spermatic  cord  (p.  253). 

The  operation  of  shortening  the  round  ligaments  is  sometimes 
carried  out  in  cases  of  retroflexion,  but  abdominal  hysteropexy, 
which  consists  in  suturing  the  fundus  to  the  anterior  abdominal 
wall,  is  more  frequently  performed. 

The  utero-sacral  ligaments  are  fibro-muscular  bands,  which 
extend  from  the  posterior  surface  of  the  uterus  just  above  the 
cervix  to  the  posterior  wall  of  the  pelvis  lateral  to  the  rectum. 
They  are  extra-peritoneal,  but  produce  peritoneal  ridges,  which 
are  known  as  the  utero-sacral  folds.  These  ligaments  may 
become  shortened,  following  inflammatory  conditions  of  the 
perimetrium,  and  drag  the  lower  part  of  the  uterus  backwards, 
giving  rise  to  acute  ante-flexion. 

In  a  retroflexed  uterus,  the  cervix  assumes  a  more  vertical 
position,  and  the  external  orifice  of  the  uterus  may  be  directed 
straight  down  the  vagina.  In  this  position,  the  flexion  at  the 
isthmus  may  be  sufficiently  pronounced  to  cause  difficulty  in 
the  evacuation  of  the  menstrual  discharge. 

The  pregnant  uterus  ascends  from  the  pelvis  into  the 
abdomen  as  it  enlarges  in  size,  but  the  retroverted  gravid  uterus 
is  prevented  from  doing  so  by  the  sacral  promontory.  The 
enlargement  of  the  viscus,  therefore,  causes  increased  intra- 
pelvic  pressure,  and  the  urethra  is  pressed  against  the  symphysis 
pubis,  causing  first  retention  of  urine,  and  later,  the  overflow 
from  a  distended  bladder.  If  the  position  of  the  uterus  is 
corrected,  the  pregnancy  will  follow  a  normal  course. 

The  Uterine  (Fallopian)  Tube  is  attached  to  the  uppermost 
part  of  the  lateral  border  of  the  uterus,  and  extends  laterally 
in  the  free  upper  margin  of  the  broad  ligament  towards  the 


392  THE  ABDOMEN  AND  PELVIS 

pelvic  wall,  where  it  is  closely  related  to  the  medial  surface  of 
the  ovary  (Fig.  117). 

The  part  of  the  tube  which  is  embedded  in  the  uterine  wall 
is  known  as  the  pars  uterina.  Lateral  to  it,  the  tube  possesses 
for  a  short  distance  well-marked  longitudinal  and  circular 
muscular  coats.  In  this  portion,  which  is  termed  the  isthmus, 
the  lumen  is  very  small.  Lateral  to  the  isthmus,  the  muscular 
coat  is  not  so  strongly  developed,  but  the  mucous  coat  is  very 
much  thicker.  This  part  of  the  tube  is  known  as  the  ampulla, 
and  its  extremity  widens  out  into  the  infundibulum,  which  is  a 
funnel-like  depression,  the  walls  of  which  are  formed  by  numerous 
narrow  processes,  called  the  fimbria.  These  processes  project 
from  the  broad  ligament,  and  are  completely  covered  by 
peritoneum.  One  of  them,  the  fimbria  ovarica,  is  constantly 
attached  to  the  upper  pole  of  the  ovary.  At  the  bottom  of  the 
infundibulum,  the  uterine  tube  communicates  with  the  peritoneal 
cavity  through  the  ostium  abdominale,  and  at  this  point  the 
peritoneal  endothelium  merges  into  the  ciliated  epithelium 
which  lines  the  tube. 

As  the  ova  are  discharged  from  the  ovary,  they  pass  at  once 
into  the  peritoneal  cavity,  and  only  those  that  gain  entrance  to 
the  ostium  abdominale  have  any  chance  of  becoming  fertilised. 
Occasionally,  a  fertilised  ovum  fails  to  be  carried  along  the 
tube  into  the  uterus  and  continues  to  develop  in  the  tube  itself. 
This  condition  is  known  as  tubal  gestation,  and  as  the  ovum 
enlarges,  gives  rise  to  abdominal  symptoms,  which  are  frequently 
misinterpreted.  Tubal  abortion  may  occur  through  the  ostium 
abdominale,  and  in  this  case  the  haemorrhage  varies  in  severity. 
Occasionally,  it  is  excessive  and  calls  for  surgical  interference. 
Failing  a  tubal  abortion,  the  ovum  increases  in  size  until  the 
uterine  tube  ruptures,  when  the  extent  of  the  subsequent 
haemorrhage  will  depend  on  the  site  of  the  rupture.  If  the 
tube  gives  way  in  the  lower  two-fifths  of  its  circumference,  the 
haemorrhage  occurs  between  the  two  layers  of  the  broad  ligament, 
and  is  consequently  limited  in  amount.  On  the  other  hand, 
if  the  tube  ruptures  in  the  upper  three-fifths  of  its  circumference, 
the  haemorrhage  occurs  into  the  peritoneal  cavity,  and  unless 
it  is  restricted  by  the  partial  obliteration  of  the  cavity  owing 
to  adhesions,  it  is  so  severe  that  immediate  laparotomy  is 
imperative. 

The  Ovary  is  an  almond-shaped  body  about  i  to  i|  inches 
long  by  half  an  inch  wide.  It  projects  from  the  posterior 


THE  FEMALE  PELVIS  393 

layer  of  the  broad  ligament,  which  it  draws  out  to  form  the 
mesovarium.  It  is  covered  by  peritoneum  which  is  somewhat 
altered  in  character,  and  which  is  termed  "  germinal  epithelium." 

In  nulliparae,  the  ovary  lies  on  the  side  wall  of  the  pelvis 
in  a  small  peritoneal  recess,  termed  the  fossa  ovarica,  which  is 
limited  above  by  the  external  iliac  vessels  and  behind  by  the 
ureter.  Its  medial  surface  is  related  to  the  uterine  tube,  and 
its  anterior  border  is  connected  to  the  posterior  layer  of  the 
broad  ligament  by  the  mesovarium.  From  its  upper  pole, 
which  gives  attachment  to  the  fimbria  ovarica,  the  peritoneum 
passes  to  the  side  wall  of  the  pelvis  as  the  suspensory  ligament. 
The  lower  pole  of  the  ovary  is  attached  to  the  uterus  by  a 
fibro-muscular  band,  known  as  the  ovarian  ligament. 

The  Ovarian  Artery  arises  from  the  aorta  opposite  the 
second  lumbar  vertebra,  and  passes  downwards  and  laterally 
on  the  psoas  major  to  reach  the  brim  of  the  pelvis,  where  it 
enters  the  suspensory  ligament.  It  gives  off  a  few  twigs  to  the 
uterine  tube,  and  one  or  two  branches  which  run  medially  in  the 
mesosalpinx  to  anastomose  with  the  uterine  artery,  but  the 
main  stem  of  the  vessel  enters  the  mesovarium  to  supply  the 
ovary.  In  the  latter  part  of  its  course  the  artery  is  very  tortuous, 
and  is  surrounded  by  the  pampiniform  plexus  of  veins,  which 
unite  to  form  the  ovarian  vein  in  the  suspensory  ligament. 

Owing  to  the  free  anastomosis  of  the  ovarian  and  uterine 
arteries,  the  peritoneum  on  each  side  of  the  ovary  must  be 
seized  with  forceps  when  the  organ  is  being  removed.  Ligature 
of  the  vessels  should  be  carried  out  by  transfixing  the  broad 
ligament,  otherwise  the  sutures  may  slip  and  give  rise  to 
troublesome  haemorrhage  owing  to  the  retraction  of  the  cut 
vessels. 

Dermoid  or  other  cysts  arising  in  connection  with  the  ovary 
may  or  may  not  possess  a  pedicle  of  peritoneum.  When  they 
do,  the  pedicle  consists  of  the  mesovarium  and  its  contained 
vessels.  Twisting  of  the  pedicle  produces  kinking  of  the  artery 
and  cuts  off  the  blood-supply  of  the  tumour.  In  other  cases, 
the  cyst  may  grow  in  between  the  two  layers  of  the  broad  ligament, 
and  separate  them  as  it  enlarges.  The  peritoneum  may  be 
stripped  off  the  pelvic  wall  and  the  iliac  colon,  and  the 
commencement  of  the  pelvic  colon  may  be  denuded.  When 
the  tumour  is  removed,  great  care  must  be  exercised  lest  these 
parts  of  the  bowel  be  injured,  as  they  are  in  intimate  relationship 
with  it. 


394  THE  ABDOMEN  AND  PELVIS 

A  large  ovarian  cyst  with  a  long  pedicle  may  be  mistaken 
for  a  movable  kidney,  as  manipulations  may  be  successful  in 
placing  it  in  the  loin  (p.  353),  but  as  soon  as  the  manual  pressure 
is  taken  away,  it  tends  to  sink  down  towards  the  pelvis. 

The  Ep-oophoron  (Parovarium)  lies  between  the  two  layers  of  the  broad 
ligament  below  the  ampulla  of  the  uterine  tube.  Cysts  of  the  ep-oophoron 
rarely  possess  a  pedicle,  and,  as  they  enlarge,  they  separate  the  two  layers  of 
the  broad  ligament.  The  ep-oophoron  represents  a  persistent  part  of  the 
Wolffian  body  (p.  267)  and  consists  of  a  number  of  small  vertical  tubules, 
which  join  a  horizontal  duct.  This  duct  usually  ends  blindly,  but  it  varies  in 
length  and  may  be  continued  downwards  to  the  vagina,  where  it  sometimes 
opens.  It  is  then  known  as  the  duct  of  Gartner,  and  it  corresponds  to  the 
ductus  deferens  in  the  male. 

Cysts  may  arise  in  the  lower  part  of  the  duct  and  project  into  the  vagina. 

Development  of  the  Uterus,  etc. — Shortly  after  the  appearance  of 
the  Wolffian  ducts  (p.  267),  two  other  longitudinal  ducts  appear.  These 
are  known  as  the  Mullerian  ducts.  At  their  cephalic  extremities  they  open 
into  the  body- cavity,  and  their  caudal  extremities,  though  ending  blindly  at 
first,  subsequently  open  into  the  lowest  part  of  the  cloaca.  The  caudal 
two-thirds  of  the  Mullerian  ducts  fuse  to  form  the  uterus  and  vagina,  but 
their  cephalic  thirds  remain  separate  and  form  the  uterine  (Fallopian)  tubes. 
The  latter  retain  their  primitive  connection  with  the  body-cavity  as  the  ostium 
abdominale. 

The  two  Mullerian  ducts,  although  lying  side  by  side,  may  fail  to  fuse. 
In  this  case,  the  vagina  is  divided  into  right  and  left  halves  by  a  median 
septum  and  the  uterus  is  bicornuate.  The  condition  of  bicornuate  uterus 
with  a  normal  vagina  is  not  uncommon. 

At  first,  the  Mullerian  duct  is  represented  by  a  solid  column  of  cells,  which 
later  become  canaliculised.  If  this  process  is  not  carried  out  completely, 
the  condition  of  atresia  vagina  is  brought  about. 

A  few  of  the  tubules  of  the  Wolffian  body  persist  -in  the  female  as  the 
ep-oophoron  (parovarium),  and  they  retain  their  connection  with  the  Wolffian 
duct,  which  is  known,  in  the  adult,  as  the  duct  of  Gsertner. 

Lymph  Vessels  of  the  Female  Generative  Organs.  —  The 

lymph  vessels  from  the  body  and  fundus  of  the  uterus  run 
laterally  in  the  broad  ligament.  The  majority  of  them, 
accompanied  by  the  lymph  vessels  from  the  ovary  and  the 
uterine  tube,  ascend  from  the  pelvis  and  join  the  lumbar  lymph 
glands.  Of  the  remainder  some  pass  to  the  external  iliac 
group  and  others  associate  themselves  with  the  round  ligament, 
to  terminate  in  the  medial  group  of  the  superficial  subinguinal 
lymph  glands. 

The  lymph  vessels  from  the  cervix  uteri  and  the  upper  part 
of  the  vagina  end  in  the  hypogastric  lymph  glands,  but  those 
from  the  posterior  aspect  establish  connections  with  the  ano- 
rectal  lymph  glands  (p.  372),  on  the  walls  of  the  rectal  ampulla. 

The  lymph  vessels  from  the  lower  part  of  the  vagina  join  the 
medial  group  of  the  superficial  subinguinal  lymph  glands  (p.  400). 

The  Uterine  Artery,  a  branch  of  the  hypogastric,  curves 


THE  FEMALE  PELVIS  395 

forwards  and  medially  on  the  pelvic  floor  till  it  reaches  the 
base  of  the  broad  ligament.  It  then  runs  medially  between 
the  two  peritoneal  layers  to  the  lateral  border  of  the  uterus. 
At  a  distance  of  three-quarters  of  an  inch,  from  the  uterus  the 
uterine  artery  crosses  above  and  anterior  to  the  ureter,  and,  in 
tying  the  vessel,  great  care  must  be  exercised  not  to  include 
the  ureter  within  the  ligature.  In  order  to  avoid  this  danger, 
the  artery  is  usually  tied  close  to  the  uterus,  as  it  lies  above 
the  lateral  fornix  of  the  vagina. 

The  uterine  artery,  after  giving  off  a  branch  which  descends 
to  supply  the  cervix  and  vagina,  ascends  along  the  lateral  border 
of  the  uterus,  supplying  it  with  numerous  branches.  Finally  it 
ends  by  supplying  the  isthmus  of  the  uterine  tube  and  by 
anastomosing  with  branches  of  the  ovarian  artery. 

Hysterectomy. — The  operation  of  removal  of  the  uterus 
has  been  much  simplified  by  the  adoption  of  the  Trendelenberg 
position  and  the  abdominal  route.  Access  is  obtained  by 
means  of  a  median  infra-umbilical  incision  (Fig.  76)  through 
the  abdominal  wall. 

The  suspensory  ligaments  of  the  ovary  and  the  round 
ligaments  are  seized  in  forceps,  to  secure  the  contained  arteries, 
and  are  then  divided.  The  ovary  and  tube  are  lifted  up  on 
each  side,  and,  lateral  to  them,  the  broad  ligaments  are  divided 
medially  and  downwards  towards  the  uterus.  Before  the 
uterus  is  reached,  artery  forceps  are  passed  downwards  and 
medially  to  secure  the  uterine  artery  in  the  interval  between 
the  point  where  it  crosses  the  ureter  and  the  point  where  it  gives 
off  its  descending  cervical  branch.  The  peritoneal  covering  of 
the  uterus  is  then  incised  transversely  in  front  and  behind  so 
as  to  join  the  incisions  already  made  in  the  broad  ligaments. 
The  fingers  are  inserted  into  the  cellular  interval  between  the 
bladder  and  the  cervix,  and  the  two  viscera  are  carefully 
separated  from  one  another.  The  uterus  is  then  dragged  up- 
wards and  the  supra- vaginal  portion  of  the  cervix  is  cut  through. 
All  the  cut  vessels  are  tied,  and,  in  order  to  prevent  slipping, 
the  ligatures  should  be  passed  through  the  peritoneum.  In 
the  case  of  the  uterine  artery,  a  secure  hold  may  be  obtained 
by  passing  the  ligature  through  the  stump  of  the  cervix. 
Subsequently,  the  cut  edges  of  the  peritoneum  are  sutured 
together  across  the  floor  of  the  pelvis,  all  the  ligatures  being 
inverted  beneath  the  peritoneum.  The  last  step  in  the  operation 
consists  in  placing  the  pelvic  colon  in  the  empty  pelvis. 


396  THE   ABDOMEN  AND   PELVIS 

Both  in  pregnancy  and  in  large  tumours  the  vascular  supply 
of  the  uterus  is  much  increased,  and  the  slipping  of  a  ligature 
gives  rise  to  formidable  haemorrhage. 

A  Vaginal  Examination  is  best  carried  out  with  the  patient 
in  the  dorsal  position,  the  thighs  being  well  flexed  and  abducted. 
The  labia  majora  should  first  be  separated,  as  this  act  draws 
apart  the  labia  minora  and  prevents  their  inversion  into  the 
vagina  by  the  examining  fingers.  The  middle  and  index  fingers 
are  then  inserted,  and  a  thorough  examination  of  the  vaginal 
fornices  may  be  made. 

Through  the  anterior  fornix  the  base  of  the  bladder  can  be 
felt,  and,  when  the  surgeon  uses  his  free  hand  to  exert  pressure 
on  the  anterior  abdominal  wall  in  a  downward  and  backward 
direction,  the  body  of  the  uterus  can  also  be  examined,  if  it  is 
in  the  normal  position.  In  the  lower  part  of  the  anterior  vaginal 
wall,  the  urethra  can  be  recognised  as  a  rounded  cord  and  may 
be  rolled  against  the  arcuate  (subpubic)  ligament. 

Through  the  posterior  fornix,  the  fingers  can  palpate  the 
contents  of  the  utero-rectal  fossa.  A  prolapsed  ovary  is  at  once 
recognised  on  examination  by  the  characteristic  sensation 
aroused  in  the  patient.  The  rectum  lies  in  close  contact  with 
the  lower  part  of  the  posterior  vaginal  wall,  and  scybalous  masses 
can  be  recognised  by  the  fact  that  they  pit  on  pressure.  When 
the  rectum  is  empty,  the  sacral  promontory  can  be  reached 
with  the  tip  of  the  forefinger.  The  distance  between  it  and  the 
pubic  symphysis  can  be  estimated ;  normally,  it  amounts  to 
4|  inches. 

Through  the  lateral  fornices,  the  conditions  of  the  broad 
ligaments  may  be  estimated,  and  tumours,  collections  of  pus 
in  the  uterine  tubes,  or  the  enlargement  due  to  extra-uterine 
pregnancy  may  be  recognised. 

The  uterine  tubes,  when  healthy,  cannot  be  palpated,  but 
in  the  presence  of  salpingitis  they  can  readily  be  made  out  on 
vaginal  examination.  When  a  calculus  is  impacted  in  the  lower 
part  of  the  ureter,  it  may  sometimes  be  located  per  vaginam, 
but  the  normal  ureter,  like  the  normal  tube,  cannot  be  felt 
through  the  fornix. 

The  Female  Perineum. — The  rectal  triangle  shows  no  differences  of 
importance,  and  the  description  given  on  pp.  373-375  holds  good  for  this  area 
in  the  female. 

In  the  urogenital  triangle  the  sexual  differences  require  further  description. 

The  labia  majora  are  two  folds  of  skin  which  surround  the  urogenital 
fissure.  They  commence  in  front  at  the  mons  veneris,  a  rounded  elevation  on 


THE  FEMALE  PELVIS  397 

the  front  of  the  pubes,  and  extend  backwards,  meeting  to  form  the  posterior 
commissure  just  anterior  to  the  anus.  Their  inner  surfaces  are  covered  by 
slightly  modified  skin,  which  is  kept  moist  by  the  secretion  of  numerous 
sebaceous  glands. 

The  labia  minora  are  two  folds  of  skin  which  lie  within  the  urogenital 
fissure,  one  on  each  side  of  the  vaginal  orifice.  Anteriorly  each  splits  into 
upper  and  lower  parts.  The  upper  parts  of  the  two  sides  unite  above  the 
clitoris  and  form  the  prceputium  ditoridis.  The  lower  parts  are  attached  to 
the  under  surface  of  the  clitoris  and  constitute  thefrenulum. 

The  clitoris  is  homologous  with  the  glans  penis  and  possesses  a  similar 
structure,  but  it  is  very  much  smaller  in  size  and  is  not  traversed  by  the  urethra. 
Dorsally  it  consists  of  two  corpora  cavernosa,  which  are  covered  distally 
by  the  glans.  In  place  of  the  corpus  cavernosum  urethrae  of  the  male,  the 
ventral  aspect  of  the  body  of  the  clitoris  is  occupied  by  a  venous  plexus, 
termed  the  pars  intermedia,  which  is  continuous  in  front  with  the  erectile 
tissue  of  the  glans. 

The  root  of  the  clitoris  consists  of  two  crura  and  the  bulb  of  the  vestibule, 
and  it  lies  in  the  superficial  perineal  pouch  (p.  376).  The  crura,  as  in  the  male, 
are  attached  to  the  borders  of  the  pubic  arch  and  are  covered  by  the  ischio- 
cavernosi  muscles.  The  bulb  of  the  vestibule  consists  of  two  elongated  bodies, 
composed  of  erectile  tissue,  which  lie  one  on  each  side  of  the  entrance  to  the 
vagina.  In  front  they  are  continuous  with  one  another  and  with  the  pars 
intermedia.  During  the  stretching  of  the  vaginal  walls  in  parturition  or  from 
trauma  these  venous  plexuses  may  be  injured  and  give  rise  to  a  haematoma. 
The  bulb  is  covered  by  the  bulbo-cavernosus  (sphincter  vaginae)  muscle. 

Between  the  glans  clitoridis  and  the  orifice  of  the  vagina  there  is  a  smooth 
triangular  area,  which  is  pierced  by  the  external  opening  of  the  urethra. 
This  area  is  termed  the  vestibule. 

The  vaginal  orifice  in  the  virgin  is  partly  obscured  by  the  hymen,  which 
consists  of  two  folds  of  mucous  membrane  of  varying  shape  and  size.  Some- 
times the  hymen  is  imperforate,  and,  with  the  onset  of  puberty,  the  condition 
gives  rise  to  trouble  by  obstructing  the  menstrual  flow. 

The  glandulce  vestibulares  majores  (of  Bartholin)  correspond  to  the  bulbo- 
urethral  glands  in  the  male  (p.  384).  They  lie  on  the  lateral  vaginal  wall, 
under  cover  of  the  bulbo-cavernosus  muscle,  and  their  ducts  open  in  the 
interval  between  the  hymen  and  the  labia  minora.  These  glands  may 
become  infected  in  gonorrhoea  and  give  rise  to  abscess  formation. 

The  Female  Urethra  is  only  i£  inches  long,  and  throughout 
its  whole  extent  it  is  closely  related  to  the  anterior  wall  of  the 
vagina.  As  in  the  male,  the  urethra  pierces  the  urogenital 
diaphragm,,  but  its  course  in  the  superficial  perineal  pouch  is 
extremely  short,  as  it  almost  at  once  opens  on  the  surface  of  the 
vestibule.  It  follows  a  slightly  curved  course,  the  concavity 
of  the  curve  being  directed  forwards,  and  it  can  readily  be 
dilated  so  as  to  permit  of  direct  examination  of  the  interior  of 
the  bladder.  The  ureteral  orifices  can  be  inspected  and  direct 
catheterisation  can  be  carried  out. 

The  vessels  and  nerves  of  the  urogenital  triangle  in  the  male 
have  been  described  on  p.  377,  and  require  no  further  mention. 


398  THE  INFERIOR  EXTREMITY 

THE  INFERIOR  EXTREMITY. 

THE   FRONT  OF  THE  THIGH. 

Surface  Landmarks. — The  bony  points  of  the  pelvis  have 
already  been  described  (pp.  237  and  239). 

> ...  The  sartorius  muscle  is  rendered  prominent  when  the  hip  and 
knee-joints  are  flexed  and  the  limb  is  rotated  laterally.  It  can 
then  be  recognised  as  a  ridge  passing  from  the  anterior  superior 
iliac  spine  obliquely  to  the  medial  side  of  the  thigh.  To  its 
lateral  side,  just  distal  to  the  anterior  superior  spine,  the  ringers 
can  be  inserted  into  a  depression,  which  is  bounded  laterally 
by  the  tensor  Jascicz  latce.  This  depression  overlies  the  straight 
head  of  the  rectus  femoris — which  lies  on  the  anterior  aspect  of 
the  capsule  of  the  hip- joint — and  it  is  rendered  more  distinct 
when  the  patient  flexes  the  thigh  with  the  knee  extended. 

The  tendon  of  the  adductor  longus,  which  arises  in  the  angle 
between  the  pubic  crest  and  the  symphysis,  can  be  seen  when 
the  thigh  is  adducted  against  resistance.  In  obese  subjects, 
though  not  always  visible,  the  tendon  can  be  felt  and  traced 
to  the  pubis.  The  tendon  may  serve  as  a  guide  to  the  pubic 
tubercle,  the  position  of  which  must  be  determined  in  distin- 
guishing a  femoral  from  a  small  inguinal  hernia.  The  neck  of 
a  femoral  hernia  lies  below  the  tubercle,  while  that  of  an  inguinal 
hernia  is  situated  above  it. 

Superficial  Vessels.— -The  great  saphenous  vein  (p.  447) 
lies  in  the  superficial  fascia  on  the  antero-medial  side  of  the 
thigh,  and,  having  received  numerous  tributaries,  pierces  the 
fascia  cribrosa,  which  partially  closes  the  fossa  ovalis  (saphenous 
opening),  to  join  the  femoral  vein. 

Its  proximal  part  is  commonly  exposed  by  the  surgeon  in 
the  removal  of  varicose  veins,  and  is  most  easily  found  by 
making  a  transverse  incision  through  the  skin  and  fascia  at  the 
distal  border  of  the  fossa  ovalis  (p.  401),  the  patient's  limb 
being  kept  slightly  abducted  and  laterally  rotated. 

At  the  point  where  the  great  saphenous  joins  the  femoral 
vein  there  is  not  uncommonly  a  dilatation,  which  gives  rise  to  a 
visible  swelling.  This  may  be  mistaken  for  a  femoral  hernia, 
as  there  is  an  impulse  on  coughing  and  the  swelling  disappears 


THE  FRONT  OF  THE  THIGH 


399 


For  the  purpose  of  differential 


when  the  patient  lies  down, 
diagnosis,  the  patient  is 
examined  in  the  recumbent 
posture,  and  a  finger  is 
placed  on  the  proximal  part 
of  the  fossa  ovalis  so  as  to 
control  the  femoral  vein 
and  also  a  femoral  hernia, 
if  one  is  present.  The 
patient  is  then  allowed  to 
resume  the  erect  attitude. 
The  swelling,  if  venous  in 
nature,  gradually  reappears 
from  below  as  the  veins  fill 
up. 

The  superficial  epigastric 
and  external pudendal  arteries 
have  been  described  on  p. 
253.  The  superficial  cir- 
cumflex iliac  pierces  the  deep 
fascia  lateral  to  the  fossa 
ovalis  and  passes  laterally 
(p.  409).  All  three  are  de- 
rived from  the  femoral 
artery. 

The  Cutaneous  Nerves  which 
supply  the  skin  of  the  front  of 
the  thigh  arise  from  the  lumbar 
plexus. 

1.  The    lateral    cutaneous  (L.    nerve 
2,   3)    enters    the    thigh    behind 

the  lateral  extremity  of  the  in- 
guinal ligament,  and  runs  behind 
the  deep  fascia  for  two  inches 
before  breaking  up  into  anterior 
and  posterior  divisions,  which 
pierce  the  deep  fascia  to  supply  D  eal  nerve 

the  skin  of  the  buttock  and  of         (O.T.  ant.  tibial)" 
the  lateral  aspect  of  the  thigh  as 
far  as  the  knee. 

2.  The    lumbo-inguinal   nerve 
(crural  branch  of  the  genito- crural) 
(L.  i,  2)  supplies  an  area  of  skin 
distal  to  the  intermediate  part  of 

the  inguinal  ligament.  It  varies  greatly  in  size,  and  sometimes  extends  to 
the  region  of  the  knee.  In  renal  colic,  pain  is  sometimes  referred  to  the 
areas  supplied  by  the  lumbo-  and  ilio-inguinal  nerves  (p.  354). 


Lateral  cutaneous 
nerve  of  the  thigh 

Ilio-inguinal  nerve 
Lumbo-inguinal  - — ^ 

nerve 

Branch  from 
medial  cutaneous" 
nerve  of  the  thigh 
Intermediate  cuta- 
neous nerve 
of  the  thigh 
Medial  cutaneous- 
nerve  of  the  thigh 


Great  saphenous 
vein" 


Anterior  part  of 
medial  cutaneous- 
nerve  of  the  thigh 


Infrapatellar  branch 
of saphenous  nerve" 


Great  saphenous 
vein" 

Saphenous  nerve. 
Superficial  peroneal 


FIG.  118. — The  Superficial  Nerves  and 
Veins  on  the  Anterior  Aspect  of  the 
Lower  Limb. 


400  THE  INFERIOR  EXTREMITY 

3.  The  intermediate  cutaneous  (L.  2,  3)  is  a  branch  of  the  femoral  (anterior 
crural)  nerve.     It  supplies  the  skin  of  the  front  of  the  thigh  as  far  as  the 
knee  (Fig.  118). 

4.  The  medial  cutaneous  (L.  2,  3),  also  a  branch  of  the  femoral  nerve, 
supplies  the  antero-medial  aspect  of  the  thigh.     In  the  distal  part  of  its 
course  it  is  associated  with  the  great  saphenous  vein. 

5.  The  ilio-inguinal  (L.  i)  (p.  240)  supplies  a  few  branches  to  the  skin  of 
the  proximal  and  medial  part  of  the  thigh. 

6.  The  obturator  nerve  (L.  2,  3,  4)  sends  some  branches  through  the  sar- 
torial plexus  (p.  41 1),  which  are  distributed  posterior  to  the  medial  cutaneous 
nerve. 

The  Superficial  Subinguinal  Lymph  Glands,  which  lie 
on  the  deep  fascia  distal  to  the  inguinal  ligament,  are  subdivided 
into  two  groups,  (a)  The  proximal  group  consists  of  a  chain  of 
lymph  glands  which  lie  distal  to  and,  roughly,  parallel  with 
the  inguinal  ligament.  The  lateral  members  of  the  group 
receive  afferents  from  the  perineum,  anus,  buttock,  and  the 
abdominal  wall,  below  the  umbilicus  ;  the  medial  glands  receive 
afferents  from  the  anus,  perineum,  and  external  genitalia.  (b) 
The  distal  group  lies  around  the  proximal  part  of  the  great 
saphenous  vein  and  on  the  lateral  border  of  the  fossa  ovalis 
(saphenous  opening).  This  group  receives  all  the  superficial 
lymph  vessels  of  the  lower  limb,  except  those  from  the  buttock 
and  those  from  the  lateral  side  of  the  foot  and  the  postero- 
lateral  area  of  the  leg,  which  enter  the  popliteal  glands  (p.  446). 

Lymphangitis  from  septic  conditions  of  the  toes  may  cul- 
minate in  suppurative  adenitis  of  the  distal  subinguinal  glands. 
In  these  cases  the  thigh  is  usually  kept  in  the  position  of  flexion 
in  order  to  relax  the  overlying  skin  and  cutaneous  nerves. 

The  efferents  from  both  groups  of  the  superficial  subinguinal 
lymph  glands  terminate  in  the  deep  subinguinal  glands,  which 
lie  behind  the  deep  fascia  around  the  proximal  parts  of  the 
femoral  vessels.  Abscesses  in  connection  with  this  group 
should,  therefore,  be  opened  by  Hilton's  method.  The  efferents 
from  the  popliteal  glands  also  end  in  the  deep  group,  which  sends 
its  own  efferents  to  the  external  iliac  lymph  glands.  The 
most  proximal  member  of  the  deep  group  occupies  the  femoral 
ring  (p.  403). 

The  Deep  Fascia  is  attached  proximally  to  the  body  and 
tubercle  of  the  pubis,  to  the  inguinal  ligament  and  the  anterior 
superior  iliac  spine.  Laterally,  it  encloses  the  tensor  fasciae 
latae  and  reaches  the  gluteal  region.  On  the  medial  side  it  is 
attached  to  the  margins  of  the  pubic  arch  as  far  as  the  ischial 
tuberosity,  where  it  becomes  continuous  with  the  deep  fascia 


THE  FRONT  OF  THE  THIGH 


401 


of  the  back  of  the  thigh.  It  is  particularly  strong  over  the  lateral 
aspect  of  the  thigh,  where  it  is  strengthened  by  the  insertions 
of  the  tensor  fasciae  latse  and  glutseus  maximus.  This  part  of 
the  fascia  lata  is  known  as  the  ilio-tibial  tract. 

Cut  edge  of  Scarpa's  fascia 
Lumbo-inguinal  nerve 

Femoral  vessels 

Superior  horn  of  falciform  margin 
Subcutaneous  inguinal  ring 
Pectineal  part  of  fascia  femoris     | 

Spermatic  cord 
Superficial  external 
pudendal  artery 


Superficial  epigastric 
artery 

Superficial  circum- 
flex iliac  artery 
Lymph  gland 
Iliac  portion  of 
fascia  lata 

Lateral  cutane- 
ous nerve  of  the 


Inferior  horn  of  falciform 
margin  of  fossa  ovalis.j 
Great  saphenous  ve 

Anterior  and  posterior  ( 
branches  of  the  medial  < 
cutaneous  nerve  (O.T.  V 
internal  cutaneous) 


FIG.  119. — The  Subinguinal  Lymph  Glands  and  the  Fossa  Ovalis 
(Saphenous  opening). 

A  large  gap,,  termed  the  fossa  ovalis  (saphenous  opening), 
occurs  in  the  deep  fascia  just  distal  to  the  medial  end  of  the 
inguinal  ligament.  The  centre  of  the  opening  lies  i|  inches 
distal  and  lateral  to  the  pubic  tubercle  (Stiles).  It  is  traversed 
by  the  great  saphenous  vein  and  is  partially  closed  by  the  fascia 
cribrosa.  The  lateral  border  of  the  fossa  ovalis  is  sharp  and 
well  denned.  It  is  falciform  in  outline,  and  its  superior  cornu 

26 


402  THE  INFERIOR  EXTREMITY 

(Key's  ligament}  arches  proximally  and  medially  to  reach  the 
pubic  tubercle,  where  it  blends  with  the  lacunar  ligament  (of 
Gimbernat).  The  inferior  cornu  (Burns'  ligament)  is  also  well 
marked,  and  lies  just  distal  to  the  point  of  union  of  the  great 
saphenous  and  femoral  veins  (Fig.  119).  The  medial  border  of 
the  fossa  is  poorly  denned.  It  is  formed  by  the  fascia  over  the 
pectineus,  and,  when  traced  laterally,  it  disappears  behind  the 
femoral  sheath  and  blends  with  its  posterior  wall. 

The  fossa  ovalis  is  i|  inches  long  by  half  an  inch  wide,  and 
is  of  particular  importance  because  it  represents  the  distal 
opening  of  the  track  taken  by  a  femoral  hernia  after  it  has 
passed  through  the  femoral  (crural)  ring  (p.  403). 

The  lateral  intermuscular  septum  is  a  strong  partition  which 
connects  the  deep  fascia  to  the  lateral  lip  of  the  linea  aspera 
of  the  femur.  It  separates  the  vastus  lateralis  from  the  femoral 
head  of  the  biceps,  and  thus  forms  a  partition  between  the 
extensor  and  flexor  compartments  of  the  thigh.  Incisions  to 
expose  the  diaphysis  of  the  femur  are  made  in  front  of  the  line 
of  the  lateral  intermuscular  septum  (p.  437). 

The  medial  intermuscular  septum  separates  the  adductor 
from  the  extensor  compartment  of  the  thigh.  As  it  covers  the 
anterior  surfaces  of  the  adductor  longus  and  magnus,  it  forms 
the  fascial  floor  of  the  adductor  canal  (of  Hunter). 

The  Femoral  Sheath  is  a  sleeve-like  prolongation  of  the 
fascial  envelope  of  the  abdomen  (p.  271)  which  passes  down  into 
the  thigh  behind  the  inguinal  ligament.  Lateral  to  the  femoral 
vessels,  both  the  fascia  transversalis  and  the  fascia  iliaca  are 
attached  to  the  inguinal  ligament;  but  opposite  the  vessels, 
which  intervene  between  the  two  layers,  they  are  carried  into 
the  thigh  to  form  the  femoral  sheath  (Fig.  120). 

Two  fascial  septa  divide  the  sheath  into  three  compartments  ; 
the  lateral  compartment  contains  the  femoral  artery  and  the 
lumbo-inguinal  nerve  and  is  the  longest  of  the  three  (Fig.  121). 
The  middle  compartment  contains  the  femoral  vein.  The 
medial  compartment,  which  is  the  shortest  of  the  three,  only 
contains  some  extra-peritoneal  fat  and  one  of  the  deep  sub- 
inguinal  lymph  glands,  which  together  constitute  the  septum 
femorale  (crurale) ;  it  is  known  as  the  femoral  (crural)  canal,  and 
is  of  great  importance  because  it  constitutes  the  passage  through 
which  a  femoral  hernia  enters  the  thigh. 

The  femoral  sheath  is  related  anteriorly  to  the  fascia  lata 
and  the  fossa  ovalis  ;  posteriorly,  it  rests  on  the  pectineus, 


THE  FRONT  OF  THE  THIGH 


403 


medially,  and  on  the  psoas  major,  laterally.  Between  these 
two  muscles  the  posterior  wall  of  the  sheath  is  connected  to  the 
capsule  of  the  hip-joint. 

The  mouths  of  the  central  and  lateral  compartments  of  the 
sheath  are  completely  filled  by  their  contents,  but  the  mouth 
of  the  femoral  canal,  which  is  termed  the  femoral  (crural)  ring, 
is  occupied  only  by  a  lymph  gland,  and  therefore  constitutes 
a  weak  point  in  the  fascial  envelope  of  the  abdomen.  In  addi- 
tion to  its  fascial  walls,  the  femoral  ring  is  bounded  anteriorly 


Skin 

Fascia  of  Camper 
Fascia  of  Scarpa 
Ext.  oblique  aponeurosis 
Int.  oblique 

Transversus 
Fascia  transversalis- 
Peritoneun 

Fascia  iliaca' 
Femoral  ring" 
Deep  subinguinal  gland 
Septum  femorale. 
Pectineus- 
Fossa  ovalis- 


Superior  ramus  of  pubis 


FIG.  120.— Diagram  of  a  Sagittal  Section  through  the  lower  part  of  the 
Abdomen  and  the  proximal  part  of  the  Thigh.  The  section  passes 
through  the  femoral  canal  and  demonstrates  the  mode  of  formation  of 
the  femoral  sheath. 

by  the  inguinal  ligament,  laterally  by  the  femoral  vein,  pos- 
teriorly by  the  pectineus  and  the  subjacent  ramus  of  the  pubis, 
and  medially  by  the  free,  lateral  margin  of  the  lacunar  ligament 
(of  Gimbernat). 

In  a  Femoral  Hernia  the  bowel  pushes  the  parietal  peri- 
toneum of  the  lower  part  of  the  anterior  abdominal  wall  and 
the  extra-peritoneal  fat  (septum  femorale,  p.  402)  through  the 
femoral  ring  into  the  femoral  canal.  It  stretches  the  anterior 
wall  of  the  sheath  and  thus  gains  another  covering.  The  sac, 
together  with  its  coverings,  passes  through  the  fascia  lata  at 
the  fossa  ovalis,  and  then,  following  the  course  of  least  resist- 
ance, bends  upwards  towards  the  anterior  superior  iliac  spine 

26  a 


404  THE  INFERIOR  EXTREMITY 

in  the  lax,  fatty  space  which  contains  the  proximal  subinguinal 
lymph  glands. 

During  attempts  to  reduce  a  femoral  hernia  the  thigh  should 
be  semiflexed  and  slightly  adducted  in  order  to  relax  the  pec- 
tineus,  the  fascia  lata,  and  the  inguinal  ligament.  Gentle 
manipulations  are  then  carried  out  to  make  the  protrusion 
retrace  the  course  of  its  original  path,  first  distally  and  medially 
till  it  passes  through  the  fossa  ovalis,  and  finally,  backwards 
and  proximally  through  the  femoral  ring. 

The  surgical  approach  may  be  by  means  of  an  incision  parallel 
and  just  distal  to  the  medial  part  of  the  inguinal  ligament, 
or  a  semilunar  incision  may  be  utilised,  the  base  of  the  flap 
being  medial,  with  the  object  of  keeping  the  wound  as  far  as 
possible  from  the  genitalia.  After  division  of  the  skin,  super- 
ficial fascia  and  vessels,  a  little  blunt  dissection  reveals  a  mass 
of  fat  quite  distinct  from  the  surrounding  fatty  areolar  tissue. 
The  coverings  derived  from  the  fascia  cribrosa  and  the  wall  of 
the  femoral  canal  can  rarely  be  identified.  Further  blunt  dis- 
section is  carried  out  until  the  neck  of  the  tumour  is  isolated  at 
the  femoral  ring,  and  while  this  is  being  done  the  union  of  the 
great  saphenous  with  the  femoral  vein  may  be  exposed  just 
proximal  to  the  distal  edge  of  the  fossa  ovalis.  The  fatty  tissue, 
which  consists  of  the  septum  femorale,  is  then  carefully  incised 
step  by  step  in  a  search  for  the  hernial  sac.  Sometimes  there 
is  no  sac  and  the  tumour  is  simply  a  lipoma  growing  in  the 
septum  femorale.  If  a  sac  is  found  it  is  carefully  isolated, 
ligated,  and  transplanted  upwards  by  carrying  the  long  ends  of 
the  ligatures  upwards  through  the  femoral  ring  and  bringing 
them  out  above  the  inguinal  ligament  and  there  tying  them. 

Many  methods  have  been  introduced  in  order  to  close,  narrow, 
or  obstruct  the  femoral  canal,  but  owing  to  the  rigidity  of  the 
parts  above  and  the  constant  movements  of  the  parts  below, 
none  of  them  have  proved  altogether  satisfactory.  A  strong 
purse-string  catgut  suture  may  be  utilised  to  pucker  up  the  fascia 
in  the  region.  It  is  passed  through  the  inguinal  ligament,  the 
fascia  lata,  the  lateral  border  of  the  fossa  ovalis,  and  the  fascia 
over  the  pectineus,  and  care  must  be  taken  not  to  injure  the 
femoral  vein.  Another  method  is  to  dissect  up  a  flap  of  the  pec- 
tineal  fascia  and  stitch  it  to  the  inguinal  ligament,  thus  closing 
the  femoral  ring. 

Femoral  hernia  occurs  more  frequently  in  women  than  in 
men.  This  is  partly  on  account  of  the  greater  width  of  the 


THE  FRONT  OF  THE  THIGH  405 

pelvis  and  the  increased  size  of  the  femoral  ring,  and  partly 
because  the  peritoneal  fossa,  which  lies  opposite  the  ring,  is 
more  pronounced  in  the  female.  In  young  girls  and  female 
infants  inguinal  hernia  (p.  264)  is  the  commoner  variety,  but 
after  puberty  femoral  hernia  is  the  commoner  of  the  two. 

Owing  to  the  narrowness  of  the  canal  and  the  unyielding 
character  of  its  walls,  the  occurrence  of  irreducible  femoral 
epiplocele  is  not  uncommon,  and  femoral  hernias  frequently 
become  strangulated.  In  operating  on  a  strangulated  femoral 
hernia,  some  difficulty  may  be  experienced  in  recognising  the 
sac  when  it  is  reached  on  account  of  the  cedema  and  congestion. 
All  the  layers  must  be  divided  until  the  escape  of  the  discoloured 
fluid  from  within  the  sac  indicates  the  proximity  of  the  bowel. 
Before  the  condition  of  the  gut  at  the  constricted  neck  can  be 
examined  and  the  hernia  reduced  the  femoral  ring  must  be  en- 
larged. Owing  to  the  nature  of  the  boundaries  of  the  ring 
(p.  403)  this  can  only  be  carried  out  on  the  medial  side.  A 
director  is  passed  along  the  medial  side  of  the  neck  of  the  sac 
and  a  guarded  knife  is  introduced.  Two.  or  three  small  incisions 
are  made  in  the  free  edge  of  the  lacunar  ligament  (of  Gimbernat), 
until  the  opening  is  sufficiently  enlarged  to  permit  of  the  bowel 
being  withdrawn  for  examination.  In  a  very  small  percentage 
of  cases  this  proceeding  is  at  once  followed  by  severe  haemorrhage, 
due  to  injury  of  an  abnormal  obturator  artery.  Normally  the 
obturator  artery  (p.  411)  arises  from  the  hypogastric,  but  in 
about  20  per  cent  of  cases  it  arises  from  the  inferior  (deep) 
epigastric  (Fig.  121).  In  its  subsequent  course  towards  the 
obturator  foramen  it  may  pass  either  to  the  medial  or  lateral 
side  of  the  femoral  ring.  When  the  artery  passes  medial  to 
the  ring  it  is  apt  to  be  injured  when  the  lacunar  ligament  is 
incised  in  relieving  the  strangulation  of  a  femoral  hernia.  If 
the  bleeding  points  cannot  be  caught  it  will  be  necessary  to  cut 
down  on  and  ligature  the  inferior  epigastric  artery  (p.  253). 

Cold  abscesses  originating  in  connection  with  the  vertebral 
column  or  the  hip- joint  may  give  rise  to  a  swelling  in  the  proximal 
part  of  the  thigh.  As  they  possess  an  impulse  on  coughing, 
and  disappear  or  decrease  in  size  in  the  recumbent  position, 
they  may  be  mistaken  for  femoral  hernise.  The  point  at  which 
they  emerge  from  behind  the  inguinal  ligament  may  clear  up 
the  diagnosis,  for  the  neck  of  a  femoral  hernia  is  always  placed 
distal  to  the  medial  extremity  of  the  ligament,  whereas  a  cold 
abscess  appears  to  the  lateral  side  of  the  femoral  vessels  (p.  522). 


4o6  THE  INFERIOR  EXTREMITY 

The  Femoral  Trigone  (of  Scarpa)  is  a  triangular  space  lying  immediately 
distal  to  the  inguinal  ligament,  which  forms  its  base.  Its  oblique  lateral 
boundary,  formed  by  the  sartorius,  and  its  straight  medial  boundary,  formed 
by  the  medial  border  of  the  adductor  longus,  meet  one  another  at  the  apex 
of  the  triangle. 

The  floor  of  the  space  is  formed,  in  its  lateral  part,  by  the  iliacus  and 
psoas  major,  as  they  cross  the  front  of  the  hip- joint  to  reach  the  lesser  tro- 
chanter.  The  medial  part  of  the  floor  is  formed  by  the  pectineus  proximally 
and  the  adductor  longus  distally  (Fig.  121). 

The  most  important  contents  of  the  space  are  the  femoral  vessels  and 
nerve,  together  with  their  large  branches. 

The  Femoral  (Anterior  Crural)  Nerve  (L.  2,  3,  4) 
enters  the  thigh  by  passing  behind  the  inguinal  ligament  half 
an  inch  lateral  to  the  femoral  artery.  In  the  pelvis  the  nerve 
lies  deep  to  the  fascia  iliaca.  In  the  thigh  it  lies  in  the  groove 
between  the  psoas  major  and  the  iliacus,  and  is  covered  over  by 
the  fascia  lata,  which  is  usually  thickened  in  this  situation. 
The  nerve  at  once  breaks  up  into  (i)  cutaneous,  (2)  muscular, 
and  (3)  articular  branches. 

(1)  The  medial  and  intermediate  cutaneous  nerves  are   de- 
scribed on  p.  400. 

The  saphenous  nerve  (L.  3  and  4)  runs  medially  and  distally 
towards  the  femoral  artery,  and  at  the  apex  of  the  femoral 
trigone  it  enters  the  adductor  canal  (of  Hunter).  It  leaves  the 
canal  at  its  distal  end  and  pierces  the  deep  fascia  near  the 
adductor  tubercle,  where  it  becomes  associated  with  the  great 
saphenous  vein.  Its  terminal  branches  are  distributed  to  the 
medial  side  of  the  leg  and  foot  (p.  499). 

(2)  The  muscular  branches  of  the  femoral  nerve  supply  the 
pectineus,  the  sartorius,  and  the  quadriceps  extensor. 

(3)  Articular  branches  arise  from  the  nerves  to  the  vasti 
and  supply  the  knee-joint,  while  the  nerve  to  the  rectus  femoris 
gives  off  a  branch  to  the  hip-joint.     In  addition  to  receiving 
branches  from  the  femoral  nerve,  both  joints  are  supplied  by 
the  obturator  nerve  (p.  411).     It  is  not  uncommon  to  find  that, 
in  tuberculous  disease  of  the  hip-joint,  the  pain  is  entirely  re- 
ferred to  the  knee.     Whether  the  pain  is  referred  to  the  joint  or 
to  the  overlying  skin,  which  is  also  supplied  by  branches  of  the 
femoral  nerve,  is  by  no  means  certain. 

The  Femoral  Artery  is  the  direct  continuation  of  the 
external  iliac.  It  enters  the  thigh  behind  the  inguinal  ligament 
at  a  point  midway  between  the  symphysis  pubis  and  the  anterior 
superior  iliac  spine  ;  and  its  course  is  represented  by  the  proximal 
two-thirds  of  the  line  joining  this  point  to  the  adductor  tubercle, 


THE  FRONT  OF  THE  THIGH 


407 


when  the  thigh   is    slightly    flexed,    abducted,    and    laterally 
rotated. 

In  its  proximal  half  the  artery  lies  immediately  behind  the 
deep  fascia  covering  the  femoral  trigone.  -It  may  be  compressed 
against  the  head  of  the  femur,  but  owing  to  the  shape  of  the 
latter,  this  method  of  occluding  the  vessel  is  unreliable.  The 


Deep  circumflex  iliac  artery 


Inferior  epigastric  artery 
\ 


Abnormal  obturator  artery 


*&) 


Lymph  gland  in 

femoral  canal 

Septa  in  femoral 

sheath 

Saphenous  nerve 


Spermatic  cord 
Lower  end  of 
femoral  sheat 
Superficial  extern; 
pudendal  artery 


Sapheno 
Adductor  longus 


Medial  cutaneous 
nerve 


Lateral  cutaneous 
nerve 


Tensor  fasciae  latae 


Lateral  edge  of 
femoral  sheath 


Intermediate 
cutaneous  nerve 


Rectus  femoris 


FIG.  121. — The  Femoral  Trigone  (of  Scarpa).  The  anterior  wall  of  the 
femoral  sheath  has  been  removed.  The  inferior  epigastric  and  the 
deep  circumflex  iliac  arteries  arise  at  a  lower  level  than  normal,  and 
the  former  gives  off  the  abnormal  obturator  artery. 

vessel  is  usually  compressed  distally  and  backwards  against  the 
superior  ramus  of  the  pubis,  which  it  crosses  as  it  enters  the 
thigh.  In  cases  of  disarticulation  at  the  hip-joint,  where  the 
vessel  is  not  at  once  exposed  and  ligated,  the  most  satisfactory 
method  of  arresting  hsemorrhage  is  by  compression  of  the 
abdominal  aorta  just  above  its  bifurcation  (Macewen). 

Ligature  of  the  femoral  artery  may  be  carried  out  close 

266 


408  THE  INFERIOR  EXTREMITY 

to  its  origin,  for  aneurism,  or  following  wounds  of  the  vessel,  or 
as  a  preliminary  step  to  a  disarticulation  at  the  hip- joint.  The 
incision  may  be  made  in  the  course  of  the  artery  or  at  right 
angles  to  it.  In  the  latter  case  the  lumbo-inguinal  nerve  (p. 
399)  is  usually  divided,  and  the  femoral  vein,  which  lies  medial 
to  the  artery,  and  the  femoral  nerve,  which  lies  to  its  lateral  side, 
run  risk  of  injury.  When  the  skin  and  superficial  fascia  have 
been  divided,  only  the  fascia  lata  and  the  anterior  wall  of  the 
femoral  sheath,  which  is  usually  adherent  to  it,  have  to  be 
incised  before  the  artery  is  exposed. 

After  ligature  of  the  femoral  artery  at  this  site,  the  circulation 
is  re-established  (i)  through  the  anastomosis  of  the  deep  circum- 
flex iliac,  from  the  external  iliac,  with  the  superficial  circumflex 
iliac  and  the  ascending  branch  of  the  lateral  circumflex ;  and 
(2)  through  the  anastomosis  in  the  region  of  the  quadrate 
tubercle  (p.  419),  where  the  gluteal  branches  from  the  hypo- 
gastric  (internal  iliac)  anastomose  with  branches  which  arise 
from  the  femoral  on  the  distal  side  of  the  ligature. 

Axial  anastomosis  of  the  femoral  artery  and  vein  has 
been  carried  out  in  this  situation  in  cases  of  threatened  gangrene. 
The  vessels  are  divided  and  the  proximal  end  of  the  artery  is 
sutured  to  the  distal  end  of  the  vein,  while  the  proximal  end  of 
the  vein  is  similarly  sutured  to  the  distal  end  of  the  artery.  In 
this  way  an  endeavour  is  made  to  reverse  the  course  of  the 
blood-stream  in  the  lower  limb. 

Ligature  of  the  femoral  artery  at  the  apex  of  the 
femoral  trigone  is  carried  out  by  means  of  an  incision  along 
the  line  of  the  vessel.  The  sartorius  is  identified  and  retracted 
to  the  lateral  side,  exposing  the  artery  just  before  it  enters  the 
adductor  canal  (of  Hunter).  In  this  situation  the  vessel  is 
crossed  by  the  medial  cutaneous  nerve,  and  the  saphenous  nerve 
may  be  either  an  anterior  or. a  lateral  relation.  Although  lying 
to  the  medial  side  of  the  artery  in  the  proximal  part  of  the 
thigh,  the  femoral  vein  occupies  a  posterior  position  at  the  apex 
of  the  trigone,  and  care  must  be  taken  not  to  injure  it  when  pass- 
ing the  ligature.  On  this  account  the  fibrous  sheath  of  the 
artery  is  opened  on  its  antero-lateral  aspect. 

After  ligature  of  the  artery  at  this  site,  the  circulation  is  re- 
established by  means  of  the  anastomosis  round  th'e  knee-joint 
(p.  445),  where  branches  which  arise  from  the  femoral  on  the 
proximal  side  of  the  ligature  communicate  with  others  which 
arise  on  the  distal  side. 


THE  FRONT  OF  THE  THIGH  409 

The  Quadriceps  Femoris  acts  as  a  powerful  extensor  of  the  knee-joint. 
It  consists  of  four  muscles,  which  are  inserted  into  the  proximal  border  of  the 
patella  by  a  common  tendon.  They  are  all  supplied  by  the  femoral  nerve 
(L.  3  and  4). 

(i)  The  Rectus  Femoris  arises  by  a  straight  head;  from  the  anterior  inferior 
iliac  spine,  and  by  a  reflected  head,  which  joins  the  former  almost  at  right 
angles,  from  the  dorsum  ilii  just  above  the  acetabulum.  Near  its  origin 
the  muscle  lies  at  the  bottom  of  the  depression  between  the  tensor  fasciae  latae 
and  the  sartorius  (p.  398),  and  is  in  close  relation  to  the  anterior  aspect  of 
the  capsule  of  the  hip-joint.  After  it  has  been  crossed  by  the  sartorius  the 
muscle  becomes  superficial,  and  it  forms  a  well-marked  elevation  in  the 
middle  line  of  the  thigh  when  the  knee  is  extended. 

(2)  The  Vastus  Intermedius  (Crureus)  arises  from  the  anterior  and  lateral 
aspects  of  the  shaft  of  the  femur.  It  is  partially  overlapped  by  (3)  the 
Vastus  Lateralis  and  (4)  the  Vastus  Medialis.  Both  these  muscles  possess 
linear  origins  from  the  linea  aspera  and  the  proximal  part  of  the  shaft  of 
the  femur,  but  although  the  vastus  medialis  covers  the  medial  aspect  of  the 
bone,  it  gets  no  fibres  of  origin  from  it. 

At  the  sides  of  the  patella  the  capsule  of  the  knee- joint  is  greatly  strengthened 
by  tendinous  expansions,  which  it  receives  from  the  vastus  lateralis  and  medialis. 

The  Sartorius  (p.  398)  forms  the  lateral  boundary  of  the  femoral  trigone 
and  the  roof  of  the  adductor  canal,  and  then  descends  vertically  on  the  medial 
aspect  of  the  thigh.  It  is  inserted  into  the  proximal  part  of  the  medial 
surface  of  the  tibia.  The  sartorius  acts  as  a  flexor  and  medial  rotator  of  the 
tibia,  and  as  a  flexor,  abductor,  and  lateral  rotator  of  the  femur.  It  is 
supplied  by  the  femoral  nerve  (L.  3  and  4). 

Branches  of  the  Femoral  Artery.— Near  its  commence- 
ment the  femoral  artery  gives  off  the  superficial  external  pudenda! 
(p.  253),  the  superficial  epigastric  (p.  253),,  and  the  superficial 
circumflex  iliac.  The  last  named  runs  laterally,  parallel  to  the 
inguinal  ligament,  and  terminates  in  the  anastomosis  around  the 
anterior  superior  iliac  spine  (p.  416). 

The  Deep  External  Pudendal  Artery  runs  medially  behind 
the  femoral  vein  and  on  the  pectineus  to  supply  the  skin  of  the 
scrotum. 

The  Profunda  Femoris  usually  arises  about  i|  inches  distal 
to  the  inguinal  ligament,  and  descends  at  first  lateral  and  then 
posterior  to  the  femoral  vessels.  At  the  upper  border  of  the 
adductor  longus  the  profunda  leaves  the  femoral  vessels  by 
passing  behind  the  muscle. 

The  profunda  gives  origin  to  several  important  branches. 

i .  The  Lateral  Circumflex,  which  sometimes  arises  from  the 
femoral,  springs  from  the  profunda  close  to  its  origin.  It  passes 
laterally,  deep  to  the  rectus  and  sartorius,  where  it  is  exposed 
in  the  anterior  route  for  excision  of  the  hip  (p.  434),  and  then 
breaks  up  into  :  (a)  an  ascending  branch,  which  joins  the  ana- 
stomosis round  the  anterior  superior  spine  of  the  ilium  (p.  416) ; 
(b)  a  transverse  branch,  which  helps  to  form  the  crucial  ana- 


4io  THE  INFERIOR  EXTREMITY 

stomosis  (p.  418) ;    and  (c)  a  descending  branch,  which  joins 
the  anastomosis  round  the  knee-joint. 

2.  The   Medial  Circumflex,    which  frequently   arises   from 
the  femoral,  takes  origin  opposite  the  lateral  circumflex,  and 
runs  backwards  between  the  pectineus  and  the  psoas  major. 
It  passes  below  the  neck  of  the  femur  and  ends  in  the  crucial 
anastomosis  (p.  418). 

3.  The  four  perforating  arteries  arise  from  the  profunda 
more  distally.    They  wind  round  the  back  of  the  femur,  giving 
off  branches  to  the  adductors,  and  gain  the  back  of  the  thigh. 
There  they  form  a  series  of  anastomotic  arches  with  one  another. 
In  addition,  the  first  perforating  joins  the  crucial  anastomosis 
(p.  418),  and  the  fourth,  which  is  the  terminal  branch  of  the 
profunda,  anastomoses  freely  with  branches  from  the  popliteal 

(P-  445)- 

The  Pectineus  arises  from  the  superior  ramus  of  the  pubis,  and  passes 
laterally  and  distally  to  be  inserted  into  the  posterior  aspect  of  the  proximal 
part  of  the  shaft  of  the  femur.  It  is  supplied  by  the  femoral  nerve  (L.  2  and 
3),  and  acts  as  an  adductor  and  flexor  of  the  thigh. 

The  Adductor  group  consists  of  four  muscles,  and  they  are  all  supplied 
by  the  obturator  nerve  (L.  2,  3,  4). 

1.  The  Gracilis  is  a  thin,  flattened  muscle  which  extends  from  the  margin 
of  the  pubic  arch  along  the  medial  side  of  the  thigh.     As  it  is  inserted  into 
the  proximal  part  of  the  tibia  near  the  semitendinosus  (p.  441),  it  acts  more 
powerfully  as  a  flexor  of  the  knee  than  as  an  adductor  of  the  hip.     In  paralysis 
of  the  ham-strings,  flexion  of  the  knee-joint  is  carried  out  satisfactorily 
by  the  gracilis,  assisted  by  the  sartorius. 

2.  The  Adductor  Longus  (p.  398)  helps  to  form  the  floor  of  the  femoral 
trigone  and  the  posterior  wall  of  the  adductor  canal,  and  consequently 
supports  the  femoral  artery  in  a  considerable  part  of  its  course.     It  is  the 
most  anterior  of  the  three  principal  adductors,  and  is  inserted  into  the  linea 
aspera. 

3.  The  Adductor  Brevis  lies  behind  the  upper  part  of  the  adductor 
longus.     It  extends  from  the  front  of  the  pubis  to  the  back  of  the  femur. 
Its  upper  border  is  in  contact  with  the  outer  surface  of  the  obturator  externus. 

4.  The  Adductor  Magnus  is  the  largest  and  most  posterior  of  the  three 
principal  adductors.     It  arises  from  the  margin  of  the  pubic  arch  and  from 
the  lower  part  of  the  ischial  tuberosity.    The  upper  fibres  are  horizontal 
and  reach  the  femur  just  distal  to  the  quadrate  tubercle  ;   the  lower  fibres 
are  almost  vertical,  and  are  inserted  into  the  adductor  tubercle  (p.  443) ; 
the  other  fibres  extend  obliquely  to  the  linea  aspera  and  the  medial  supra- 
condylar  ridge.     By  reason  of  its  vertical  fibres,  the  muscle  possesses  a 
secondary  action  as  an  extensor  of  the  hip-joint.     In  its  upper  part  the  an- 
terior surface  of  the  magnus  is  covered  by  the  brevis,  but  below  the  lower 
border  of  that  muscle  it  is  in  contact  with  the  longus,  and,  below  the  longus, 
the  magnus  forms  the  posterior  wall  of  the  adductor  canal.     In  the  latter 
part  of  its  extent  it  possesses  a  large  gap,  the  hiatus  tendineus,  which  trans- 
mits the  femoral  vessels  to  the  popliteal  fossa. 

The  adductor  magnus  receives  an  additional  nerve-supply  from  the  sciatic 
(L.  4,  5,  and  S.  i). 

The  Obturator  Externus  arises  from  the  outer  surface  of  the  obturator 


THE  FRONT  OF  THE  THIGH  411 

membrane  and  the  medial  margin  of  the  foramen,  and  its  tendon  passes 
laterally,  to  be  inserted  into  the  trochanteric  fossa.  It  lies  deeply  in  the 
interval  between  the  quadratus  femoris  and  the  inferior  gemellus,  and  is  at 
first  below  and  then  posterior  to  the  capsule  of  the  hip-joint.  It  is  supplied 
by  the  posterior  branch  of  the  obturator  nerve  (I,.  3  and  4),  and  acts  as  a 
powerful  lateral  rotator  of  the  thigh. 

Owing  to  the  tilt  of  the  pelvis,  the  outer  surface  of  the  muscle  is  directed 
distally,  laterally,  and  forwards.  It  is  in  relation  to  the  pectineus  and  the 
adductor  brevis. 

The  Obturator  Nerve  (L.  2,  3,  4)  breaks  up  into  an 
anterior  and  a  posterior  division  as  it  enters  the  upper  part 
of  the  obturator  foramen.  The  anterior  division  leaves  the  pelvis 
above  the  obturator  externus,  and  passes  distally,  first  between 
that  muscle  and  the  pectineus,  and  then  between  the  adductors 
brevis  and  longus.  It  supplies  the  two  last-named  muscles 
and  the  gracilis,  and  in  addition  gives  an  articular  branch  to 
the  hip- joint.  Further,  it  gives  origin  to  a  small  branch 
which  unites  with  a  similar  branch  from  the  medial  cutaneous 
to  form  the  sartorial  plexus.  Twigs  from  this  plexus,  which 
lies  deep  to  the  sartorius,  supply  the  skin  on  the  medial  side 
of  the  thigh. 

The  posterior  division  pierces  the  upper  part  of  the  obturator 
externus,  which  it  supplies,  and  descends  on  the  deep  surface 
of  the  adductor  brevis.  It  supplies  the  adductor  magnus  and 
gives  off  a  fine  articular  branch  to  the  knee-joint  (p.  406). 

The  Obturator  Artery  (p.  405)  accompanies  the  anterior 
division  of  the  obturator  nerve  through  the  foramen.  It 
divides  into  two  branches,  which  encircle  the  obturator  mem- 
brane deep  to  the  obturator  externus,  supplying  the  muscle 
and  giving  off  a  branch  to  the  hip- joint  (p.  438). 

Obturator  Hernia  is  of  rare  occurrence.  It  follows  the 
vessels  and  nerve  through  the  upper  part  of  the  obturator 
foramen  but  has  no  constant  relation  to  them.  The  protrusion, 
however,  causes  pressure  on  the  nerve  and  gives  rise  to  Romberg's 
symptom.  This  consists  in  tenderness  of  the  adductors,  and 
pain  referred  to  the  cutaneous  distribution  of  the  obturator 
nerve  on  the  medial  side  of  the  thigh. 

The  hernia,  which  is  usually  strangulated,  lies  behind  the 
pectineus  and  on  the  surface  of  the  obturator  externus,  causing 
a  small,  ill-defined  swelling  in  the  medio-proximal  part  of  the 
thigh  ;  the  thigh  is  kept  flexed  in  order  to  relax  the  pectineus, 
and  attempts  to  produce  extension  cause  severe  pain.  Adduc- 
tion is  also  resisted,  as  this  movement  tends  to  squeeze  the 
hernia  against  the  obturator  externus. 


4i2  THE  INFERIOR  EXTREMITY 

The  Adductor  Canal  (of  Hunter)  is  an  intermuscular 
space  on  the  medial  side  of  the  middle  third  of  the  thigh,  and 
it  contains  the  femoral  artery  and  vein  and  the  saphenous  nerve. 
The  roof  of  the  canal  is  formed  by  the  sartorius  and  a  strong 
layer  of  deep  fascia,  which  lies  behind  the  muscle.  The  lateral 

Vastus  medialis 

Profunda  femoris  artery     |        Femoral  vein 
Vastus  intermedius          |     |         I      Saphenous  nerve 
Femur  |          |     |         |       |       Femoral  artery 

Rectus  femoris 


Sartorius 
Biceps  |   Gracilis 


Semitendinosus      |        |  Adductor  Longus 

Sciatic  nerve        |         |  Adductor  brevis 

Adductor  magnus        Seinimembranosus 

FIG.  122. — Transverse  Section  through  the  Thigh,  a  little  distal  to  the 
junction  of  the  proximal  and  middle  thirds.  The  lateral  intermuscular 
septum  is  well  shown,  and  the  femoral  vessels  are  seen  in  the  abductor 
canal  (of  Hunter). 

wall  is  formed  by  the  vastus  medialis,  while  the  posterior  wall 
is  formed  by  the  adductor  longus  proximally  and  the  adductor 
magnus  distally.  At  the  distal  end  of  the  canal  there  is  a  wide 
gap  in  the  insertion  of  the  latter  muscle,  and  through  this 
opening,  which  is  termed  the  hiatus  tendineus,  the  femoral  artery 
enters  the  popliteal  fossa. 

It  may  be  necessary  to  ligature  the  femoral  artery  in  the 


THE  GLUTEAL  REGION  413 

adductor  canal  following  stab  wounds  or  in  cases  of  popliteal 
aneurism.  The  incision  is  made  in  the  line  of  the  vessel,  and 
as  it  is  deepened  through  the  superficial  fascia,  the  great  saphen- 
ous  vein  or  one  of  its  tributaries  may  require  to  be  retracted. 
The  deep  fascia  over  the  sartorius  is  very  thin,  and  when  it  has 
been  divided  the  muscle  may  be  recognised  by  the  direction  of 
its  fibres.  After  the  sartorius  has  been  retracted  medially  the 
strong  fascial  roof  of  the  canal  is  incised,  and  the  femoral  artery 
is  exposed  with  the  saphenous  nerve  on  its  anterior  surface. 
The  femoral  vein  lies  posterior  to  the  artery  in  the  proximal 
part  of  the  canal,  but  distally  it  inclines  to  the  lateral  side. 
In  passing  the  aneurism  needle  care  must  be  taken  to  avoid 
injuring  the  vein. 

After  ligature  of  the  femoral  artery  in  the  adductor  canal, 
the  collateral  circulation  is  re-established  (i)  through  the  ana- 
stomosis between  the  descending  branch  of  the  lateral  circumflex 
(p.  409)  and  the  arteria  genu  suprema  (anastomotica  magna), 
and  (2)  through  the  anastomosis  between  the  fourth  perforating 
artery  (p.  410)  and  branches  of  the  popliteal  (p.  445). 

The  arteria  genu  suprema  arises  from  the  femoral  just  before 
it  leaves  the  adductor  canal.  It  divides  into  a  saphenous 
branch,  which  becomes  superficial,  and  an  articular  branch. 
The  latter  enters  the  vastus  medialis  and  descends  on  the  femur 
to  take  part  in  the  anastomosis  around  the  knee-joint  (p.  445). 


THE   GLUTEAL   REGION. 

Bony  Landmarks. — The  ischial  tuberosity  lies  vertically 
below  the  posterior  superior  iliac  spine.  It  is  deeply  situated 
under  cover  of  the  glutseus  maximus  when  the  thigh  is  extended ; 
and  when  the  thigh  is  flexed,  although  the  muscle  slips  over  the 
tuberosity,  the  skin  and  fascise  are  no  longer  relaxed,  so  that 
the  recognition  of  this  bony  point  becomes  more  difficult. 

The  greater  trochanter  of  the  femur  lies  a  hand  -  breadth 
below  the  tubercle  on  the  iliac  crest  (p.  237).  In  a  normal 
subject  its  position  is  indicated  by  a  flattened  depression  on 
the  lateral  aspect  of  the  proximal  part  of  the  thigh,  but  in  wasted 
subjects  it  becomes  a  very  prominent  projection.  Its  lateral 
aspect  is  about  two  inches  long  by  i|  inches  wide,  and  its  margins, 
more  especially  the  posterior,  can  readily  be  felt  when  the  deep 


4i4  THE  INFERIOR  EXTREMITY 

fascia,  which  tends  to  obscure  them,  is  relaxed  by  passively 
abducting  the  thigh.  When  the  limb  is  in  this  position  the 
fingers  can  sink  into  the  trochanteric  (digital)  fossa  posteriorly, 
but  this  depression  is  occluded  in  fractures  in  this  neighbourhood. 
The  greater  trochanter  may  become  distorted,  following  its 
implication  in  fractures  or  infective  disease.  Increase  in  size 
can  be  determined  and  the  two  sides  compared  by  encircling 
both  prominences  with  the  fingers  and  thumbs. 

The  lesser  trochanter  can  be  felt  by  palpating  deeply  beneath 
the  gluteal  fold  in  the  medial  aspect  of  the  thigh,  when  the  limb 
is  extended  and  medially  rotated. 

The  iliac  crests  and  spines  have  been  described  on  pp.  237, 239. 

The  Muscular  Landmarks  of  the  buttock  are  obscured 
by  the  thick  fatty  superficial  fascia,  but  the  outline  of  the 
glutczus  maximus  can  sometimes  be  seen.  Its  lower  border 
crosses  the  centre  of  the  gluteal  fold  obliquely  downwards  and 
laterally,  and  disappears  in  the  general  contour  of  the  lateral 
aspect  of  the  thigh.  The  upper  border  of  the  muscle  descends 
obliquely  from  the  posterior  part  of  the  iliac  crest  towards  the 
apex  of  the  greater  trochanter.  When  the  thigh  is  actively 
rotated  medially,  a  muscular  elevation  at  once  appears  just 
below  and  lateral  to  the  anterior  superior  iliac  spine.  It  con- 
sists of  the  tensor  fascia  latce  superficially  and  the  glutceus 
minimus  deeply. 

The  Cutaneous  Nerves  of  the  buttock  are  derived  from  numerous  sources. 

(1)  The  terminal  branches  of  the  posterior  rami  of  L.  I,  2,  and  3  cross  the  iliac 
crest  lateral  to  the  sacro-spinalis,  and  may  descend  as  far  as  the  gluteal  fold. 

(2)  The  lateral  branches  of  the  ilio-hypogastric  (L.  i)  and  last  thoracic  nerves 
(p.  240)  cross  the  crest  at  the  iliac  tubercle  and  supply  the  skin  of  the  adjoining 
area.     (3)  Branches  from  the  lateral  cutaneous  nerve  of  the  thigh  (L.  2  and  3) 
pass  backwards  into  the  gluteal  region.     (4)  The  posterior  cutaneous  (small 
sciatic)  (S.  i,  2,  and  3)  gives  off  recurrent  branches,  which  ascend  over  the 
lower  border  of  the  glutaeus  maximus.     (5)  The  skin  near  the  middle  line  is 
supplied  by  branches  of  S.  i,  2,  and  3  (Fig.  124). 

Referred  pain  in  the  region  of  the  buttock  may  occur  in  inflammatory 
conditions  of  the  lower  part  of  the  pleura  (lateral  cutaneous  branch  of  T.  12) 
or  in  irritative  conditions  of  the  bladder  and  rectum  (posterior  cutaneous 
S.  i,  2,  and  3). 

The  Deep  Fascia  of  the  buttock  is  attached  above  to  the 
iliac  crest.  In  its  antero-superior  part,  where  it  covers  the 
glutaeus  medius,  it  is  a  strong  fibrous  sheet,  but  it  splits  at  the 
upper  border  of  the  maximus  into  two  much  weaker  layers, 
which  enclose  the  muscle.  On  the  lateral  aspect  of  the  buttock 
these  two  layers  increase  in  strength,  and  having  received  the 


THE  GLUTEAL  REGION  415 

insertion  of  the  greater  part  of  the  glutseus  maximus,  they  re- 
unite to  form  the  strong  ilio-tibial  tract  (p.  401). 

The  Glutaeus  Maximus  passes  distally  and  laterally  from 
the  posterior  part  of  the  iliac  crest  and  the  dorsum  of  the  sacrum 
to  its  insertion  into  the  deep  fascia  and  the  gluteal  tuberosity 
of  the  femur.  It  is  supplied  by  the  inferior  gluteal  nerve  (L.  5, 
S.  i  and  2)  and  acts  as  an  extensor,  abductor,  and  lateral  rotator 
of  the  thigh.  Owing  to  the  great  bulk  of  the  muscle,,  it  is  ex- 
tremely difficult  to  determine  fluctuation  under  cover  of  it. 
The  fasciculi  of  which  it  is  made  up  are  very  coarse  and  can 
readily  be  separated  without  damage.  They  run  distally  and 
laterally,  and  incisions  into  the  buttock  are  therefore  made  in 
the  same  direction.  In  flexion  of  the  thigh  the  posterior  border 
of  the  greater  trochanter  passes  backwards  beneath  the  upper 
border  of  the  glutseus  maximus  when  the  muscle  is  well  developed. 
The  movement  of  medial  rotation  at  once  disengages  the  tro- 
chanter, and  the  muscle  slips  off  with  an  audible  sound.  The 
condition,  which  is  termed  "  snapping-hip,"  may  be  produced 
voluntarily,  and  it  was  formerly  thought  to  be  due  to  a  partial 
subluxation  at  the  joint.  A  layer  of  fat  underlies  the  glutseus 
maximus,  and  it  may  be  the  site  of  cellulitic  infection  following 
intra-pelvic  or  ischio-rectal  abscesses.  The  infection  spreads 
through  the  greater  or  lesser  sciatic  foramen,  and  it  penetrates 
the  parietal  pelvic  fascia,  which  closes  the  foramina,  by  tracking 
along  the  gluteal  and  the  internal  pudendal  vessels  (p.  417). 
A  large  and  constant  bursa  intervenes  between  the  muscle  and 
the  ischial  tuberosity,  and  when  inflamed  gives  rise  to  a  painful 
swelling.  Such  a  bursitis  requires  to  be  differentiated  from  a 
gumma  and  from  a  cold  abscess  (p.  522),  which  may  both  occur 
in  this  situation. 

Two  other  bursce  are  found  near  the  insertion  of  the  muscle, 
one  between  its  fascial  insertion  and  the  greater  trochanter  (p. 
433)  and  the  other  between  its  tendon  and  the  vastus  lateralis. 
They  are  both  liable  to  tuberculous  synovitis,  and  the  resulting 
cold  abscess  may  spread  (i)  distally  along  the  lateral  surface  of 
the  thigh  under  the  fascia  lata  or  (2)  backwards  and  distally 
under  the  glutseus  maximus  to  point  in  the  gluteal  fold. 

These  bursae  are  frequently  infected  with  tuberculous  disease 
and  may  be  approached,  by  a  U-shaped  incision.  The  anterior 
limb  of  the  incision  lies  behind  the  posterior  border  of  the 
tensor  fasciae  latae,  and  the  posterior  limb  divides  the  proximal 
part  of  the  insertion  of  the  glutseus  maximus.  The  transverse 


4i6  THE  INFERIOR  EXTREMITY 

part  of  the  incision  lies  distal  to  the  greater  trochanter.  Free 
exposure  is  necessary,  as  the  bursae  when  diseased  may  possess 
extensive  prolongations. 

The  glutaeus  maximus  covers  most  of  the  dorsum  ilii  and 
the  muscles,  to  which  it  gives  origin,  and  both  the  sacro-tuberous 
and  the  sacro-spinous  (greater  and  lesser  sacro-sciatic)  ligaments. 
In  addition,  it  covers  both  the  greater  and  lesser  sciatic  foramina 
and  the  vessels  and  nerves  which  they  transmit  (Fig.  123). 

The  Piriformis  (p.  355)  emerges  from  the  greater  sciatic  foramen,  and, 
as  it  passes  laterally  to  the  apex  of  the  greater  trochanter,  it  lies  on  the  postero- 
superior  aspect  of  the  capsule  of  the  hip-joint.  It  abducts  the  thigh,  and 
receives  its  nerve-supply  from  S.  i  and  2. 

The  Glutaeus  Medius  is  exposed  above  the  upper  border  of  the  maximus, 
but  its  posterior  part  is  covered  over  by  that  muscle.  It  arises  from  the  dorsum 
ilii,  and  is  inserted  into  an  oblique  ridge  which  runs  forwards  and  distally 
across  the  lateral  aspect  of  the  greater  trochanter.  The  lower  or  posterior 
border  of  the  medius  lies  along  the  upper  border  of  the  piriformis. 

The  Glutaeus  Minimus  arises  from  the  dorsum  ilii,  under  cover  of  the 
medius.  As  it  passes  to  its  insertion  on  the  anterior  aspect  of  the  greater 
trochanter,  the  muscle  is  closely  related  to  the  superior  aspect  of  the  capsule 
of  the  hip-joint. 

Both  the  glutaeus  medius  and  minimus  act  as  powerful  abductors  of  the 
thigh,  but,  in  addition,  their  anterior  fibres,  which  lie  deep  to  the  tensor 
fasciae  latas,  assist  in  medial  rotation.  The  nerve-supply  to  both  muscles  is 
derived  from  the  superior  gluteal  (L.  4  and  5,  S.  i). 

The  Superior  Gluteal  Artery,  a  branch  of  the  hypogastric 
(p.  369),  enters  the  buttock  through  the  greater  sciatic  foramen 
between  the  adjoining  borders  of  the  piriformis  and  the  glutseus 
medius.  It  possesses  a  short  trunk,  which  divides  into  a  super- 
ficial and  a  deep  division.  The  former  enters  the  maximus  and 
the  latter  breaks  up  into  upper  and  lower  branches,  which  pass 
laterally  between  the  medius  and  the  minimus. 

The  upper  branch  terminates  in  the  region  of  the  anterior 
superior  iliac  spine,  where  it  anastomoses  with  the  superficial 
and  deep  circumflex  iliac  arteries  (p.  253)  and  the  ascending 
branch  of  the  lateral  circumflex.  This  anastomosis  constitutes 
a  connection  between  the  hypogastric  (internal  iliac)  and  the 
external  iliac  trunks  (p.  408). 

The  superior  gluteal  artery  may  require  to  be  ligated  either 
for  aneurism  or  following  stab  wounds  in  the  buttock.  The 
incision  is  made  parallel  to  the  fibres  of  the  glutseus  maximus, 
and  its  centre  lies  at  the  junction  of  the  upper  and  middle  thirds 
of  the  line  joining  the  posterior  superior  iliac  spine  to  the  greater 
trochanter.  Owing  to  the  depth  at  which  the  vessel  lies  and 
the  shortness  of  its  main  trunk,  the  incision  should  be  a  fairly 
large  one. 


THE  GLUTEAL  REGION 


417 


The  Superior  Gluteal  Nerve  (L.  4,  5,  S.  i)  accompanies  the 
artery,  and  supplies  the  glutaeus  medius  and  minimus  and  the 
tensor  fasciae  latae. 

Several  important  structures  leave  the  pelvis  through  the 
greater  sciatic  foramen  at  the  lower  border  of  the  piriformis. 
They  include  (i)  the  sciatic  nerve,  (2)  the  posterior  cutaneous 
(small  sciatic)  nerve  of  the  thigh,  (3)  the  pudendal  nerve,  (4) 


Superior  gluteal  artery 
Superficial  division     i 


Superior  branch  of  deep  division 
Inferior  branch  of  deep  division 


Inferior 
gluteal  n. 
Internal 
pudendal  a.  "~ 
Nerve  to  obtu- 
rator internus  •" 

Sacro-tuberous 
ligament 

Tuber  ischii 


Biceps  femoris 
Semitendinosus 


Glutaeus'minimus 

Tensor  fasciae  latae 


Glutaeus  medius 
Sciatic  n. 
Superior  gemellus 

irator  internus  tendon 

Inferior  gemellus 
Ascending  branch  of 
medial  circumflex  a. 

Greater  trochanter 


Quadratus  femoris 
Posterior  cutaneous  n.  of  thigh 
Insertion  of  glutaeus  maximus 


FIG.  123.  —  The  Gluteal  Region.     The  glutaeus  maximus  has  been  divided,  and 
the  glutaeus  medius  has  been  removed  from  its  origin  and  turned  down. 


the  nerve  to  obturator  internus,  (5)  the  inferior  gluteal  nerve, 
(6)  the  inferior  gluteal  (sciatic)  vessels,  and  (7)  the  internal 
pudendal  vessels. 

The  pudendal  nerve,  internal  pudendal  vessels,  and  the 
nerve  to  obturator  internus  cross  the  spine  of  the  ischium  and 
pass  through  the  lesser  sciatic  foramen  to  enter  the  ischio-rectal 
fossa  (p.  373).  The  vessels  may  be  injured  in  stab  wounds,  and 
can  be  exposed  by  an  incision  parallel  to  the  fibres  of  the  glutaeus 
maximus,  and  cutting  the  line  joining  the  posterior  superior 

27 


418  THE  INFERIOR  EXTREMITY 

iliac  spine  to  the  ischial  tuberosity  at  the  junction  of  its  lower 
and  middle  thirds. 

The  Sciatic  Nerve  (L.  4,  5,  S.  i,  2,  3)  emerges  below  the 
piriformis  and  passes  distally,  lying  successively  on  the  ischium, 
the  obturator  internus  and  gemelli,  and  the  quadratus  femoris. 
At  the  lower  border  of  the  quadratus  it  passes  on  to  the  posterior 
surface  of  the  adductor  magnus,  and  is  crossed  superficially  by 
the  long  head  of  the  biceps  femoris;  which  is  running  distally 
and  laterally  (Fig.  123). 

In  intractable  cases  of  sciatica  the  nerve  may  be  stretched 
by  open  operation.  The  incision  is  carried  vertically  along  the 
thigh,,  from  the  mid-point  of  the  line  joining  the  ischial  tuber- 
osity to  the  greater  trochanter.  After  division  of  the  skin  and 
fasciae,  the  lower  border  of  the  glutseus  maximus  and  the  biceps 
tendon,  which  runs  distally  and  laterally,  are  exposed.  The 
finger  is  passed  into  the  angle  between  the  two  in  a  medial 
direction,  and  the  nerve  is  hooked  up  from  under  cover  of  the 
biceps. 

The  Inferior  Gluteal  (Sciatic)  Artery  appears  at  the  lower 
border  of  the  piriformis  and  at  once  breaks  up  into  numerous 
branches.  It  can  be  exposed  by  the  incision  already  described 
for  the  ligature  of  the  internal  pudendal  artery  (p.  417). 

The  crucial  anastomosis  occurs  in  the  region  of  the  quadrate 
tubercle.  Branches  of  the  inferior  and  superior  gluteal  arteries, 
which  both  arise  from  the  hypogastric  (internal  iliac),  anastomose 
with  branches  of  the  medial  and  lateral  circumflex  arteries  and 
the  first  perforating,  which  arise  from  the  profunda  femoris. 
In  this  way  an  important  connection  is  formed  between  the 
external  iliac  and  the  hypogastric  trunks,  and  it  is  capable  of 
re-establishing  the  circulation  in  the  lower  limb,  when  the 
external  iliac  is  ligatured  or  when  the  femoral  artery  is  tied 
proximal  to  the  origin  of  its  profunda  branch  (p.  407). 

The  Posterior  Cutaneous  (Small  Sciatic)  Nerve  of  the 
thigh  (S.  i,  2,  and  3)  runs  distally,  under  cover  of  the  glutseus 
maximus  and  on  the  surface  of  the  sciatic  nerve.  At  the  lower 
border  of  the  maximus  the  nerve  crosses  the  biceps  superficially, 
and  continues  its  course  through  the  thigh  immediately  under 
the  deep  fascia  and  in  the  middle  line  of  the  limb.  It  gives  off 
twigs  to  supply  the  skin  of  the  buttock  and  of  the  posterior 
and  medial  aspects  of  the  thigh  (Fig.  124). 

Hernias  may  escape  from  the  pelvis  through  the  greater 
sciatic  foramen  and  appear  at  the  upper  or  lower  border  of  the 


THE  GLUTEAL  REGION 


419 


as   superior   or  inferior  gluteal 


Plit.^ 

yilfb^ 


piriformis.  They  are  known 
hernia.  The  former  variety 
is  the  less  uncommon,  and 
it  occurs  more  often  in  the 
female  and  on  the  right  side 
of  the  body.  The  neck  of 
the  sac  lies  in  the  fossa 
ovarica  (p.  393)  in  the  angle 
between  the  obturator  and 
the  hypogastric  arteries. 
If  the  hernia  becomes 
strangulated,  the  constric- 
tion at  the  neck  should  be 
divided  in  a  downward  and 
lateral  direction,  parallel  to 
the  fibres  of  the  piriformis. 

The  tendon  of  the  obturator 
interims  (p.  355)  leaves  the  pelvis 
through  the  lesser  sciatic  foramen 
and  passes  laterally  to  the  greater 
trochanter.  The  superior  and 
inferior  gemelli  are  attached  to 
its  upper  and  lower  margins. 
This  tricipital  tendon,  which 
abducts  the  thigh  and  rotates 
it  laterally,  is  closely  related  to 
the  posterior  aspect  of  the  cap- 
sule of  the  hip-joint.  The  ob- 
turator internus  is  supplied  by 
a  special  branch  from  the  sacral 
plexus  (L.  5,  S.  i,  2). 

The  quadratus  femoris  is 
placed  at  a  slightly  lower  level. 
Its  fibres  are  practically  horizon- 
tal and  extend  from  the  ischial 
tuberosity  to  the  quadrate  tub- 
ercle on  the  intertrochanteric 
crest  (posterior  intertrochanteric 
line),  so  that  the  muscle  acts  as 
a  lateral  rotator  and  also  as  an 
adductor.  It  receives  a  special 
branch  from  the  sacral  plexus 
(L.  4,  5,  S.  i). 

The    Hip-Joint    is 

formed  by  the  articulation    FlGp  ^4. -The  Cutaneous  Nerves  on  the 

Posterior  Aspect  of  the  Lower  Limb, 
of  the  rounded  head  of  the 

femur  with  the  cup-shaped  acetabulum  on  the  lateral  aspect 
of  the  hip-bone.    The  ilium,  ischium,  and  pubis  all  share  in 

27  a 


Lumbar  nerves 

Cutaneous  branches 

of  the  1 2th  thoracic 

and  ilio-hypogastric 

nerves 

Sacral  nerves 

Perforating 
cutaneous 

Branches  from 

posterior  cutaneous  - 

nerve  of  the  thigh 

Lateral  cutaneous 

nerve  of  the  thigh 

Long  perineal 

Posterior  cutaneous 
nerve  of  the  thigh 

Medial  cutaneous 
nerve  of  the  thigh 

Lateral  cutaneous 
nerve  of  the  thigh 


Medial  cutaneous 
nerve  of  the  thigh 


Anastomotic  peroneal 
nerve 

Posterior  cutaneous 
nerve  of  the  thigh 


Medial  cutaneous  nerve 
of  the  calf  (O.T.  ramus  — 
communicans  tibialis) 

Nervus  suralis 
(O.T.  short  saphenous) 


Medial  calcanean  branch 


420  THE  INFERIOR  EXTREMITY 

the  formation  of  the  acetabulum,  and  at  birth  they  are  separated 
from  one  another  by  a  triradiate  bar  of  cartilage.  Secondary 
centres  of  ossification  appear  in  this  cartilage  about  the  twelfth 
year,  and  the  acetabulum  is  completely  ossified  by  the  sixteenth 
or  seventeenth  year  (Fig.  126). 

The  articular  cartilage  forms  a  broad  strip  round  the 
acetabulum  near  its  circumference,  but  the  floor  of  the  cavity 
and  the  acetabular  (cotyloid)  notch  are  non-articular. 

At  birth  the  proximal  end  of  the  femur  is  entirely  cartil- 
aginous. The  neck  of  the  femur  is  ossified  by  a  proximal 
extension  from  the  diaphysis,  and,  as  it  forms,  it  divides  the 
cartilaginous  extremity  into  two  parts,  which  it  separates  from 
one  another.  The  more  proximal  of  these  forms  the  head.  A 
centre  of  ossification  appears  in  it  during  the  first  year,  and  it 
unites  with  the  neck  during  the  twentieth  year.  The  more 
distal  forms  the  greater  trochanter,  which  begins  to  ossify  in 
the  second  year  and  joins  the  shaft  at  19.  The  secondary 
centre  for  the  lesser  trochanter,  which  unites  with  the  shaft 
at  1 8,  does  not  appear  till  the  eighth  to  the  twelfth  year. 

The  articular  head  of  the  femur  forms  rather  more  than 
half  a  sphere.  A  little  below  and  behind  its  centre  there  is  a 
non-articular  depression  for  the  attachment  of  the  ligamentum 
teres. 

The  Labrum  Glenoidale  (cotyloid  ligament)  is  a  strong 
fibre-cartilaginous  ring  attached  to  the  circumference  of  the 
acetabulum,  and  serving  both  to  deepen  its  cavity  and  to  reduce 
the  diameter  of  its  inlet.  It  is  accurately  fitted  round  the  head 
of  the  femur,  and  even  after  the  joint  has  been  opened  it  is 
not  easy  to  pull  the  head  of  the  femur  out  of  the  acetabulum. 

The  Transverse  Ligament  bridges  across  the  acetabular 
notch,  and  completes  the  circumference  of  the  acetabulum. 

The  Capsule  of  the  hip- joint  is  of  great  strength.  Proximally, 
it  is  attached  to  the  bony  circumference  of  the  acetabulum, 
the  labrum  glenoidale,  and  the  transverse  ligament  (Fig.  125). 
Distally,  it  is  attached  to  the  neck  of  the  femur ;  anteriorly, 
this  attachment  is  along  the  intertrochanteric  line;  but  pos- 
teriorly, it  crosses  the  middle  of  the  femoral  neck — i.e.  the  whole 
of  the  anterior  surface  and  the  medial  half  of  the  posterior 
surface  of  the  femoral  neck  lie  within  the  capsule. 

The  capsule  is  strengthened  by  certain  accessory  ligaments. 

i.  The  Ilio-Femoral  Ligament  is  a  well-marked  thickening 
of  the  anterior  aspect  of  the  capsule.  It  is  attached  proximally 


THE  HIP- JOINT  421 

to  the  anterior  inferior  iliac  spine,  just  below  the  origin  of  the 
straight  head  of  the  rectus  femoris.  Distally  it  divides  into  two 
parts,  which  are  respectively  attached  to  the  upper  and  lower 
portions  of  the  intertrochanteric  line. 

The  medial,  longer  limb  of  the  ilio-femoral  ligament  sustains 
the  forward  pressure  of  the  femoral  head  when  the  body  is  in 
the  erect  attitude,  and  prevents  hyperextension  of  the  joint. 
The  shorter,  lateral  limb  prevents  too  great  a  degree  of  adduction 
and  lateral  rotation,  as  these  movements  render  it  tense. 

2.  The   Pubo-Capsular   Ligament    strengthens   the   infero- 
medial  part  of  the  capsule.     It  becomes  tense  during  the  move- 
ment of  abduction. 

3.  The  Ischio-Capsular  Ligament  is  a  much  weaker  band, 
which  is  placed  in  relation  to  the  posterior  aspect  of  the  capsule. 
It  helps  to  prevent  too  great  a  degree  of  medial  rotation. 

Although  it  is  usually  complete,  the  capsule  is  occasionally 
interrupted  by  a  communication  between  the  joint  cavity  and 
the  bursa  under  the  psoas  major  (p.  273).  This  opening  lies 
between  the  medial  limb  of  the  ilio-femoral  and  the  pubo- 
capsular  ligament. 

The  ligamentum  teres  is  intra-capsular  but  extra-synovial. 
It  is  attached  distally  to  the  head  of  the  femur  and  proximally 
to  the  transverse  ligament  and  the  edges  of  the  acetabular 
notch.  It  is  completely  surrounded  by  a  tube  of  synovial 
membrane  (Fig.  125). 

The  Synovial  Membrane  of  the  hip-joint  covers  the  deep 
surface  of  the  capsule,  and  at  the  distal  attachment  of  the 
latter  is  reflected  on  to  the  femoral  neck,  where  it  is  thrown 
into  numerous  parallel  ridges,  known  as  the  retinacula.  At 
the  attachment  of  the  capsule  to  the  transverse  ligament,  the 
synovial  membrane  forms  a  tube  round  the  ligamentum  teres 
and  also  covers  the  pad  of  fat  (Haversian  gland)  which  occupies 
the  floor  of  the  acetabulum  (Fig.  125). 

Spread  of  Tuberculous  Disease  in  the  Region  of 

the  Hip-Joint. — Tuberculous  disease  in  the  region  of  the  hip- 
joint  commences  most  frequently  in  the  neck  of  the  femur,  near 
its  lower  surface,  and  close  to  the  epiphyseal  cartilage  of  the 
head  of  the  bone.  It  is  in  the  first  place  extra-synovial  but 
intra-capsular,  and,  on  this  account,  infection  of  the  hip-joint 
occurs  with  great  frequency.  As  the  disease  progresses  it 
reaches  the  surface  of  the  bone,  destroys  the  periosteum,  and 
invades  the  synovial  membrane.  These  changes  are  usually 

27  & 


422 


THE  INFERIOR  EXTREMITY 


accompanied  by  a  reactionary  effusion  within  the  joint.  If 
this  effusion  occurs  early  in  the  disease,  adhesions  may  form 
between  the  synovial  membrane  of  the  femoral  neck  and  that 
lining  the  capsule  and  delay  the  extension  of  the  disease  into  the 
joint.  Such  adhesions  give  rise  to  limitation  of  movement, 


Labruni  glenoidale 


Head  of  femur 


Acetabular  pad 


Capsule  of  hip-joint 


Articular  artery 

Transverse  acetabular 
ligament 


FIG.  125. — Oblique  Section  through  Right  Hip-Joint,  showing  the  relation 
of  the  Capsule  to  the  Epiphysis  of  the  Head  of  the  Femur. 

Light  blue  =  articular  cartilage.  Green  =  periosteum. 

Striped  blue  =  ligaments.  Red  =  synovial  membrane. 

which  may  be  the  first  sign  of  the  disease.  In  the  absence 
of  adhesions,  the  disease  rapidly  becomes  intra- synovial  and 
attacks  the  articular  cartilage. 

If  the  disease  spreads  across  the  neck  it  may  actually  separate 
the  head  or  render  it  so  weak  that  a  diastasis  readily  occurs. 
Only  very  exceptionally  does  the  disease  perforate  the  epiphyseal 
cartilage  and  invade  the  epiphysis  from  without  the  joint. 


THE  HIP-JOINT  423 

Tuberculous  disease  may  originate  in  any  of  the  three  com- 
ponent parts  of  the  acetabulum  (p.  419);  and  in  this  case  the 
spread  to  the  joint  is  prevented  only  by  the  articular  cartilage, 
i.e.  no  epiphysis  intervenes  between  the  joint  cavity  and  the 
tuberculous  focus. 

The  diaphyseal  side  of  the  epiphysis  for  the  greater  trochanter 
constitutes  a  third  site  for  the  occurrence  of  tuberculous  disease 
in  this  region.  Spread  may  take  place  (a)  down  the  shaft,  as 
an  osteo-myelitis  ;  (b)  along  the  neck,  ultimately  involving  the 
joint ;  or  (c)  through  the  periosteum  in  front  of  or  behind 
the  trochanter,  giving  rise  to  abscess  and  sinus  formation. 
Tuberculous  abscesses  in  the  region  of  the  hip,  however,  much 
more  commonly  have  their  origin  within  the  joint. 

When  the  disease  becomes  intra-synovial  the  pus  eventually 
perforates  the  capsule  at  its  weakest  points,  which  are  found 
(i)  postero-laterally,  and  (2)  anteriorly,  between  the  ilio-femoral 
and  pubo-capsular  ligaments. 

1.  After  perforating  the  postero-lateral  part  of  the  capsule 
the  pus  gravitates  distally  and  backwards  to  point  near  the 
gluteal  fold,  but  it  occasionally  travels  forwards  deep  to  the 
glutseus  maximus  and  the  tensor  fasciae  latse  to  point  in  the 
interval  between  the  latter  muscle  and  the  sartorius  (p.  398). 

2.  The  course  taken  by  pus,  after  perforating  the  anterior 
aspect  of  the  capsule,  is  by  no  means  constant,     (a)  If  the  joint 
cavity  communicates  with  the  psoas  bursa  (p.  273)  the  pus 
ascends  within  the  bursa  to  the  iliac  fossa  and  the  pelvis.     It 
may  here  be  pointed  out  that  a  psoas  abscess  may  infect  the 
bursa,  and,  spreading  in  the  opposite  direction,  may  involve 
the  hip-joint,     (b)  The  pus  may  gravitate  along  the  tendon  of 
the  psoas  major  and  then  follow  the  course  of  the  medial  circum- 
flex artery  (p.  410).     It  reaches  the  dorsum  above  the  upper 
border  of  the  adductor  magnus  and  points  in  the  gluteal  fold. 
(c)  Sometimes,  after  following  the  psoas  major  tendon,  the  pus 
passes  laterally  along  the  lateral  circumflex  artery  and  reaches 
the  surface  in  the  gluteal  fold  or  in  the  neighbourhood  of  the 
greater  trochanter.     In  the  former  case,  the  condition  has  to  be 
diagnosed  from  a  tuberculous  infection  of  the  bursse  underlying 
the  tendon  of  the  glutseus  maximus. 

3.  More  rarely  the  pus  perforates  the  inferior  aspect  of  the 
capsule,  and  at  once  comes  into  relation  with  the  obturator 
externus  (p.  410).     By  following  this  muscle  to  its  insertion  the 
pus  again  reaches  the  gluteal  fold,  but  if  it  tracks  in  the  opposite 

27  c 


424  THE  INFERIOR  EXTREMITY 

direction  it  comes  to  the  surface  on  the  proximo-medial  part 
of  the  thigh. 

Intra-Pelvic  Spread. — When  tuberculous  disease  originates 
in  the  acetabulum,  it  may  not  only  infect  the  joint  but  it  may 
spread  inwards  to  the  pelvis.  The  course  taken  by  the  pus  in 
the  latter  case  depends  on  whether  it  pierces  the  pelvic  wall 
above  or  below  the  line  of  origin  of  the  levator  ani  (Fig.  114). 
In  the  former  case  the  pus  pierces  the  parietal  pelvic  fascia  and 
lies  in  the  subperitoneal  areolar  tissue.  It  may  track  along  the 
rectum,  or  it  may  fill  up  the  pelvis  till  it  overflows  through 
the  obturator  foramen  or  escapes  into  the  thigh  behind  the 
inguinal  ligament.  When  it  pierces  the  pelvic  wall  below  the 
line  of  origin  of  the  levator  ani,  the  pus  at  once  gains  the  ischio- 
rectal  fossa  and  gravitates  downwards  to  point  near  the  anus. 

Owing  to  the  possibility  of  intra-pelvic  spread,  digital 
examination  of  the  pelvis  should  be  carried  out  per  rectum  in 
every  case  of  tuberculous  disease  of  the  hip-joint. 

Aspiration  of  the  Hip-Joint  can  be  carried  out  by  intro- 
ducing an  exploring  needle  upwards,  backwards,  and  medially  at 
a  point  2  to  2 1  inches  distal  to  the  anterior  inferior  iliac  spine. 
The  instrument  gains  the  interior  of  the  joint  by  passing  under 
the  lateral  border  of  the  rectus  femoris  and  piercing  the  dis- 
tended capsule. 

The  following  lines  and  measurements  are  of  value  in  the 
examination  of  the  region  of  the  hip-joint. 

The  line  joining  the  highest  parts  of  the  two  greater  tro- 
chanters  passes  through  the  centres  of  the  two  acetabula.  The 
head  of  the  femur  lies  behind  the  point  of  intersection  of  this 
line  and  the  produced  lateral  line  of  the  abdomen. 

Nelaton's  line,  which  joins  the  anterior  superior  iliac  spine 
to  the  ischial  tuberosity,  passes  through  the  highest  part  of  the 
greater  trochanter.  When  the  trochanter  is  found  to  lie  above 
or  below  that  line  some  deformity  of  the  neck  of  the  femur 
must  be  present.  The  difficulty  of  accurate  localisation  of  the 
ischial  tuberosity  minimises  the  value  of  this  method  of 
examination. 

Chiene  demonstrated  the  symmetry  or  asymmetry  of  the 
trochanters  by  comparing  the  line  joining  their  highest  points 
with  the  line  joining  the  anterior  superior  spines.  This  method 
is  of  service  when  the  deformity  is  unilateral,  as  the  lines  are 
then  no  longer  parallel,  but  it  may  fail  to  indicate  a  bilateral 
deformity. 


THE  HIP- JOINT  425 

Bryant's  method  involves  the  measurement  of  the  vertical 
distance  between  the  highest  point  on  the  greater  trochanter 
and  the  horizontal  plane  passing  through  the  anterior  superior 
iliac  spines.  This  distance  is  normally  .about  two  inches. 
Asymmetry  points  to  unilateral  deformity  and  symmetrical 
measurements,  with  marked  deviation  from  the  normal  two 
inches,  to  bilateral  deformity. 

A  comparison  of  the  length  measurements  of  the  two  limbs 
is  of  great  value  to  the  surgeon  in  relation  to  injury  or  disease 
in  the  region  of  the  hip.  Before  proceeding  with  the  actual 
measurements,  it  is  very  important  to  see  that  the  pelvis  is  not 
tilted  to  one  side  and  to  make  certain  that  the  patient's  limbs 
are  both  in  exactly  the  same  position.  To  discover  any  lateral 
tilting  of  the  pelvis,  a  line  is  drawn  from  the  anterior  superior 
spine  of  the  ilium  at  right  angles  to  the  linea  alba,  and  this, 
when  produced,  should  pass  through  the  anterior  superior  spine 
of  the  other  side. 

Measurements  should  be  taken  from  the  anterior  superior 
spine  to  the  distal  margin  of  the  medial  condyle  of  the  femur 
and  from  that  point  to  the  medial  malleolus,  and  these  measure- 
ments should  be  compared  with  those  obtained  on  the  opposite 
limb.  From  this  comparison  any  inequality  of  the  two  limbs 
can  be  referred  to  the  bone  at  fault,  either  the  femur  or  the  tibia 
as  the  case  may  be,  and  this  method  is  therefore  of  much  greater 
value  than  the  direct  measurement  from  the  anterior  superior 
spine  to  the  medial  malleolus.  When  femoral  shortening  is 
discovered,  the  deformity  can  be  referred  to  the  shaft  or  the  neck 
by  comparing  the  measurements  from  the  tips  of  the  greater 
trochanters  to  the  distal  borders  of  the  lateral  condyles.  If 
these  are  found  to  be  equal,  the  deformity  must  be  in  the  femoral 
neck.  Shortening  of  the  femoral  or  tibial  shaft  may  arise  as  a 
result  of  infantile  paralysis. 

It  is  by  no  means  unusual  for  the  length  measurements  to 
show  trifling  differences,  and,  unless  this  exceeds  half  an  inch, 
no  stress  should  be  laid  on  it. 

The  measurements  are  usually  carried  out  with  the  patient 
in  the  dorsal  decubitus,  and  care  must  be  taken  to  see  that  the 
limbs  have  the  same  position  relative  to  the  trunk  as  they  have 
in  the  erect  attitude.  This  precaution  is  essential,  as  the  distance 
between  the  anterior  superior  spine  and  the  medial  condyle  is 
definitely  shorter  in  abduction  than  it  is  in  adduction  of  the 
thigh.  Hence  if  the  diseased  limb  is  abducted,  it  is  shortened, 


426  THE  INFERIOR  EXTREMITY 

and  if  the  sound  limb  is  adducted  so  as  to  be  parallel  to  it,  it  is 
lengthened  proportionately.  The  difference  between  the  length 
measurements  will,  therefore,,  be  very  considerable. 

A  convenient  method  of  comparing  the  lengths  of  the  lower 
limbs  can  be  used  in  children.  The  patient  is  placed  on  his 
back;  and  care  is  taken  to  see  that  the  limbs  are  symmetrically 
disposed  and  that  the  pelvis  is  not  tilted.  With  the  knees 
extended,  the  thighs  are  semi-flexed  at  the  hips  so  that  the 
soles  point  upwards.  The  relative  positions  of  the  heels  are 
at  once  demonstrated. 

Examination  of  the  Hip-Joint  and  Proximal  Ex- 
tremity Of  the  Femur.— The  patient  should  be  completely 
stripped  and  asked  to  walk  if  possible,  as  the  gait  may  be  of 
assistance  in  determining  the  diagnosis.  Any  limitation  of 
active  movement,  the  presence  of  a  limp  or  lurch,  and  the  way 
in  which  the  feet  are  placed  on  the  ground  should  all  be  observed 
with  great  care. 

After  this  inspection  the  patient  should  be  placed  on  his 
back  on  a  hard,  firm  surface.  The  bony  prominences  on  each 
side  can  then  be  carefully  marked,  and  while  this  is  being  done 
palpation  and  comparison  of  the  trochanters  may  be  carried 
out  and  the  position  of  the  femoral  head  may  be  determined. 
The  measurements  of  both  limbs  are  next  taken  and  the  various 
lines  (p.  424)  may  be  utilised. 

Lastly,  the  extent  and  nature  of  passive  movements  must 
be  examined.  These  movements,  which  comprise  flexion, 
extension,  abduction,  adduction,  circumduction,  and  rotation 
are  first  carried  out  on  the  healthy  limb  in  order  to  test  their 
normal  extent  and  to  gain  the  confidence  of  the  patient.  Next 
the  movement  of  hyperextension  is  tested,  with  the  patient  in 
the  prone  position.  The  pelvis  is  fixed  by  a  hand  placed  on  the 
sacrum  ;  and  the  other  hand,  placed  under  the  thigh,  hyper- 
extends  the  limb  by  lifting  it  from  the  table.  Differences  in 
the  extent  of  symmetrically  arranged  passive  movements,  with 
or  even  without  differences  in  length  measurements,  are  most 
valuable  in  diagnosis. 

The  use  of  radiograms  has  made  the  diagnosis  of  disease  or 
injury  in  the  region  of  the  hip-joint  much  more  certain. 

Function  of  the  Hip -Joint. — In  contradistinction  to  the 
shoulder-joint,  where  free  mobility  is  the  first  essential,  the 
chief  characteristic  of  the  hip-joint  is  its  stability.  Consequently, 
in  the  treatment  of  pathological  conditions  of  the  joint,  the  chief 


THE  HIP-JOINT  427 

aim  of  the  surgeon  is  to  obtain  a  stable  joint.  If  a  movable 
joint  can  be  obtained  at  the  same  time,  the  result  will  be  so 
much  the  better,  but  mobility  without  stability  is  of  no  value. 

The  weight  of  the  trunk  is  transmitted  to  the  femoral  heads 
through  the  upper  parts  of  the  acetabula,  and  thence  is  trans- 
mitted down  the  limbs  to  the  ground. 

In  order  to  increase  the  power  and  mobility  of  the  lower 
limb  and  to  distribute  the  weight  of  the  body  over  a  wider  base, 
the  neck  of  the  femur  is  inclined  to  the  shaft  at  an  angle  which 
varies  from  160°  in  the  child  to  110°  in  the  adult,  i.e.  with  the 
constant  increase  in  body-weight  the  angle  deviates  more  and 
more  from  160°. 

Abnormal  alterations  of  the  angle  may  seriously  interfere 
with  the  mobility  of  the  hip-joint.  In  cases  of  early  extensive 
infantile  paralysis  of  the  lower  limb,  and  in  congenital  dislocation 
of  the  hip,  the  angle  remains  of  the  infantile  type,  since  the 
head  and  neck  of  the  femur  are  not  used  to  support  their  share 
of  the  body-weight.  This  condition  is  known  as  coxa  valga. 

In  constitutional  diseases,  such  as  rickets,  and  following 
injuries  to  the  neck  of  the  femur  during  infancy,  the  body- 
weight  acting  on  softened  bone  produces  an  abnormal  decrease 
of  the  angle,  which  in  some  cases  may  be  reduced  to  45°.  This 
condition  is  termed  coxa  vara. 

Abduction  of  the  thigh  is  markedly  limited  in  coxa  vara, 
as  the  greater  trochanter  impinges  too  soon  on  the  ilium.  In 
coxa  valga,  on  the  other  hand,  abduction  is  a  very  free  movement, 
but  adduction  is  correspondingly  limited. 

Injuries  of  the  Neck  of  the  Femur.— In  the  infant,  the 
cartilaginous  proximal  extremity  of  the  femur,  which  includes 
both  the  head  and  the  neck,  may  be  fractured.  The  injury 
often  occurs  in  the  following  way.  When  an  infant,  held  in 
the  nurse's  arms,  throws  itself  backwards,  the  weight  of  its  body 
stretches  the  strong  ilio-femoral  ligament  across  the  anterior 
surface  of  the  head  of  the  femur.  If  the  child's  limbs 
were  not  held  by  the  nurse  the  pull  of  the  body-weight  on  the 
ligament  would  flex  the  thigh  and  relieve  the  strain,  but  as 
the  limbs  are  firmly  held,  the  cartilaginous  neck  of  the  femur 
gives  way,  since  the  ilio-femoral  ligament  is  too  strong  to  yield. 

In  the  child,  injury  in  this  region  may  result  in  a  green-stick 
fracture,  as  the  cartilaginous  neck  is  undergoing  ossification. 
Radiograms  have  shown  that  this  accident  is  by  no  means  rare, 
and  it  is  probably  one  of  the  most  frequent  causes  of  coxa  vara. 


428  THE  INFERIOR  EXTREMITY 

At  school  age,  injury  in  this  region  may  take  the  form  of  a 
separation  of  the  epiphysis  of  the  femoral  head.  The  correct 
diagnosis  of  this  condition  is  extremely  important,  as  unless 
proper  treatment  is  carried  out  the  epiphysis  unites  in  a  faulty 
position,  and  subsequent  limitation  of  movement  results.  After 
union  has  occurred  no  manipulations  can  separate  the  fragment 
for  the  purpose  of  reposition  in  correct  alignment. 

This  injury  is  usually  caused  by  violent  rotatory  movements 
of  the  trunk  while  the  body-weight  is  being  supported  on  the 
femur.  When  examined  the  limb  is  found  to  be  powerless, 
and  there  is  marked  eversion  together  with  some  slight  shorten- 
ing. The  diagnosis  should  be  confirmed  by  the  X-rays. 

Dislocations  of  the  Hip-Joint  may  be  (i)  Congenital, 
(2)  Traumatic,  or  (3)  Pathological. 

(i)  CONGENITAL  DISLOCATION  of  the  hip-joint  occurs  more 
frequently  in  females  than  in  males,  and  this  incidence  is  possibly 
due  to  the  fact  that  in  the  female  the  acetabulum  looks  more 
directly  to  the  lateral  side. 

The  head  of  the  femur  is  situated  on  the  dorsum  ilii  just 
lateral  to  the  anterior  inferior  spine,  and  is  enclosed  within 
the  untorn  but  greatly  stretched  articular  capsule.  In  these 
cases  it  is  doubtful  whether  the  head  of  the  bone  has  ever  occupied 
the  acetabulum,  which  is  usually  rudimentary.  The  capsule 
possesses  its  normal  attachments,  but,  owing  to  the  stretching 
to  which  it  has  been  subjected,  it  resembles  an  hour-glass  in 
shape.  When  the  child  begins  to  walk,  the  proximal  part  of 
the  capsule  has  to  transmit  the  body-weight  to  the  femur,  and 
the  condition  becomes  more  exaggerated.  The  child  walks 
with  a  heavy  downward  lurch  to  the  affected  side,  and  the 
muscles  connecting  the  trunk  to  the  thigh  become  greatly 
shortened.  The  longer  the  condition  is  allowed  to  remain  un- 
treated, the  more  difficult  will  it  be  to  carry  out  remedial 
measures  and  the  poorer  the  subsequent  result. 

Owing  to  the  shortening  of  the  muscles  it  may  be  difficult 
to  place  the  head  of  the  femur  in  the  acetabulum,  but  the 
reduction  does  not  involve  the  passage  of  the  head  through 
a  tear  in  the  capsule,  as  in  the  case  of  a  traumatic  dislocation. 
Since  the  Socket  of  the  acetabulum  may  be  undeveloped  or 
rudimentary,  it  is  a  matter  of  great  difficulty  to  retain  the  head 
of  the  femur  in  place  after  the  reduction  has  been  effected. 
Further,  the  proximal  part  of  the  hour-glass  shaped  capsule 
becomes  nipped  between  the  two  articular  surfaces. 


THE  HIP-JOINT 


429 


After  the  muscles  have  been  thoroughly  stretched,  torn,  or 
divided  by  tenotomy,  the  head  is  placed  in  the  acetabulum, 
and  the  limb  is  fixed  in  plaster  of  Paris  with  the  thigh  abducted 


FIG.  126. — Congenital  Dislocation  of  the  Hip-Joint  in  a  Child  aged  five. 
The  head  of  the  femur  is  not  in  the  acetabulum,  and  the  angle  of  the 
neck  is  greater  than  normal.  The  femur  is  medially  rotated.  Observe 
the  epiphyses  for  the  head  of  the  femur  and  the  greater  trochanter.  The 
dark  area  passing  through  the  acetabulum  corresponds  to  two  of  the 
limbs  of  the  triradiate  bar  of  cartilage. 

to  a  right  angle  and  laterally  rotated — the  "  frog  "  position. 
When  this  is  done,  the  head  of  the  femur  can  be  felt  anterior 
to  the  acetabulum,  where  a  distinct  depression  existed  prior 


430  THE  INFERIOR  EXTREMITY 

to  the  manipulations.  Subsequently,  the  plaster  case  is  renewed 
every  three  months,  and  on  each  occasion  the  limb  is  slightly 
lowered  and  the  amount  of  lateral  rotation  similarly  decreased. 
At  the  end  of  fourteen  to  twenty  months  the  limbs  should  be  in 
a  normal  position  and  walking  may  be  resumed. 

(2)  TRAUMATIC  DISLOCATION  of  the  hip  is  comparatively  rare, 
owing  to  the  fact  that  the  arrangement  of  the  bones  renders 
the  joint  osseously  strong.  For  the  same  reason,  fractures  are 
relatively  much  more  frequent. 

In  "  regular  dislocations  "  the  ilio -femoral  ligament  is  not 
damaged  or  only  its  lateral  limb  is  torn.  When  both  limbs 
of  the  ilio-femoral  ligament  are  injured,  or  when  portions  of  the 
head  of  the  femur  or  the  acetabulum  are  fractured,  the  disloca- 
tion is  termed  "  irregular." 

(a)  Regular  Dislocations. — The  tear  in  the  capsule  is  usually 
inferior  or  postero -inferior,  and  the  position  which  the  head  of 
the  femur  takes  up,  after  passing  through  it,  depends  partly 
on  muscular  action  and  partly  on  the  position  of  the  limb 
relative  to  the  pelvis  at  the  time  of  the  accident.  If  the  injury 
is  produced  by  a  heavy  weight  falling  on  the  sacrum  when  the 
subject  is  in  a  stooping  attitude  with  the  lower  limbs  flexed 
and  rotated  medially — the  common  position  at  the  time  of  the 
accident — the  head  of  the  femur  passes  posteriorly  on  to  the 
dorsum  ilii.  The  rarer  anterior  dislocation  occurs  when  the 
limbs  are  abducted  and  rotated  laterally. 

1.  The  Sub-acetabular  Dislocation  is  the  first  stage  in  all 
varieties  of  regular  dislocations,  but  the  head  seldom  remains 
in  this  position.     On  leaving  the  lower  part  of  the  capsule  the 
femoral  head  at  once  encounters  the  obturator  externus,  and  it 
may  pass  backwards,  either  above  or  below  the  tendon,  or  it 
may  pass  forwards  on  to  the  surface  of  the  muscle. 

2.  Dorsal    Dislocation. — In    the    commonest    form    of   this 
variety,  the  femoral  head  passes  backwards  above  the  obturator 
externus  and  then  ascends,  either  tearing  through  or  passing 
in  front  of  the  obturator  internus  and  the  piriformis.     It  comes 
to  rest  on  the  dorsum  ilii  between  the  piriformis  and  the  glutseus 
medius.     Owing  to  the  slope  of  the  ilium,  the  articular  head  is 
directed  backwards  and  the  greater  trochanter  forwards,  i.e. 
the  limb  is  inverted,  and  it  is  maintained  in  this  position  by 
the  tension  of  the  lateral  limb  of  the  ilio-femoral  ligament.     In 
addition,  the  thigh  is  slightly  flexed. 

The  flexion,  medial  rotation,  shortening,  and  constrained 


THE  HIP- JOINT  431 

attitude  of  the  limb  are  characteristic,  and  serve  to  distinguish 
this  dislocation  from  other  injuries. 

More  rarely,  the  neck  of  the  femur  becomes  caught  beneath 
the  obturator  internus.  The  attitude  of  the  limb  resembles 
that  found  in  the  variety  just  described,  but  the  flexion  and 
rotation  are  more  exaggerated.  The  head  may  injure  the 
sciatic  nerve,  which  is  stretched  across  it  in  the  interval  between 
the  inferior  gemellus  and  the  quadratus  femoris. 

The  lateral  limb  of  the  ilio-femoral  ligament  is  the  important 
agent  in  maintaining  medial  rotation,  and  when  it  is  torn  the 
limb  adopts  an  everted  position  (Bigelow). 

3.  Anterior  Dislocation. — From  the  subacetabular  stage,  the 
head  may  pass  forwards  and  medially  in  front  of  the  obturator 
externus.  The  greater  trochanter  is  directed  backwards  and 
laterally,  and  the  limb  is  kept  abducted,  extended,  and  laterally 
rotated,  the  eversion  being  produced  and  maintained  by  the  ilio- 
femoral  ligament.  This  variety  is  sometimes  referred  to  as 
the  "  thyroid  dislocation." 

The  head  may  pass  still  further  in  an  upward  direction, 
injuring  the  pectineus  and  adductor  muscles,  and  it  subsequently 
comes  to  rest  somewhere  between  the  anterior  inferior  iliac  spine 
and  the  pubic  tubercle,  constituting  the  pubic,  subspinous,  and 
pectineal  varieties. 

(b)  Irregular  Dislocations  are  usually  caused  by  extreme 
violence  and  the  position  taken  up  by  the  head  is  very  inconstant, 
but  it  often  tends  to  pass  downwards  and  backwards  towards 
the  lesser  sciatic  foramen  ;  the  limb  is  usually  everted  (Bigelow). 
When  the  ilio-femoral  ligament  is  ruptured,  the  femoral  head 
may  pass  backwards  below  the  obturator  externus  tendon,  which 
is  consequently  stretched  across  the  upper  aspect  of  the  neck. 
The  head  then  assumes  a  position  in  the  neighbourhood  of  the 
ischial  tuberosity. 

In  the  Reduction  of  a  Dislocation  of  the  Hip  the  head  of 
the  bone  is  made  to  retrace  its  course  through  the  tear  in  the 
capsule. 

i.  In  the  posterior  group  the  limb  is  kept  flexed  and  adducted 
by  the  tension  of  the  ilio-femoral  ligament,  which  must  first  be 
relaxed  by  flexing  and  adducting  the  thigh  still  further.  As  the 
thigh  is  carried  upwards  and  medially,  the  head  of  the  femur 
passes  downwards  and  laterally  and  approaches  the  level  of  the 
tear  in  the  capsule,  but  it  is  still  posterior  to  the  acetabulum. 
The  thigh  is  next  circumducted  and  laterally  rotated.  This 


432  THE  INFERIOR  EXTREMITY 

movement  renders  the  relaxed  ilio-femoral  ligament  tense,,  and 
it  may  be  used  as  the  fulcrum  of  a  lever  which  has  the  femoral 
shaft  for  its  long  arm  and  the  neck  for  its  short  arm.  The 
movement  of  lateral  rotation  levers  the  head  forwards  over 
the  posterior  margin  of  the  acetabulum,  and,  by  completing 
the  circumduction  and  finally  extending  the  limb,  the  head  is 
made  to  travel  medially  and  upwards  into  its  socket. 

2.  In  the  anterior  group  the  method  followed  is  much  the 
same  as  the  foregoing,  but  the  movements  are  carried  out  in 
the  reverse  direction.  The  tense  ilio-femoral  ligament  maintains 
the  femur  in  a  position  of  extension,  abduction,  and  lateral 
rotation,  and  it  must  be  relaxed  by  flexing  the  abducted  thigh 
in  order  to  release  the  head  from  its  pubic  position.  As  the 
thigh  is  elevated,  the  head  descends  to  the  level  of  the  acetabulum, 
and  it  is  made  to  travel  laterally  by  circumducting  the  fully 
flexed  thigh  in  a  medial  direction.  Finally,  the  limb  is  extended, 
and  this  movement  carries  the  head  forwards  and  medially  into 
the  acetabulum. 

(3)  PATHOLOGICAL  DISLOCATIONS  of  the  hip-joint  are  preceded 
by  atrophy  of  the  surrounding  muscles  from  disuse  and  by  soften- 
ing of  the  articular  capsule.  Sometimes,  as  in  advanced  tubercle, 
the  acetabular  margin  or  the  head  of  the  femur  is  much  eroded. 
In  these  cases  the  joint  cavity  is  often  distended  by  fluid  or 
granulations,  and  the  thigh  is  maintained  in  the  position  of  semi- 
flexion,  since  the  capacity  of  the  hip -joint  is  greatest  in  that 
attitude.  When  the  limb  is  adducted,  the  head  of  the  bone 
gradually  perforates  the  weakened  capsule,  but  this  causes  so 
little  pain  that  it  may  escape  notice  until  the  general  condition 
has  been  recovered  from. 

It  should  be  pointed  out  that  pathological  dislocations  of 
the  hip-joint  are  always  posterior,  owing  to  the  position  of  the 
limb  at  the  time  of  their  occurrence. 

The  Surgical  Approach  to  the  Hip-Joint  is  planned 
so  as  to  give  good  exposure  while  doing  little  damage.  The 
operation  of  excision  yields  excellent  results,  sometimes  even 
in  cases  of  advanced  tuberculous  disease.  As  a  rule  a  posterior 
dislocation  is  present,  or  there  may  have  been  erosion  of  the 
neck  of  the  femur,  so  that  the  head  lies  loose  in  the  acetabulum. 
On  this  account  the  joint  is  best  approached  from  behind — 
Kocher's  postero-lateral  route. 

The  upper  half  of  the  incision  corresponds  to  the  lower 
two-thirds  of  the  line  joining  the  posterior  superior  iliac  spine 


THE  HIP- JOINT  433 

to  the  greater  trochanter,  and  is  in  the  direction  of  the  fibres 
of  the  glutseus  maximus.  In  its  lower  half  the  incision  is  carried 
vertically  across  the  greater  trochanter,  splitting  the  ilio-tibial 
tract.  The  wound  is  deepened  through  the,  glutseus  maximus, 
above  and  below,  and  it  opens  into  the  bursa  between  the 
tendon  of  the  muscle  and  the  greater  trochanter.  A  large 
angular  flap,  consisting  of  skin,  fasciae,  and  the  glutseus  maximus, 
can  now  be  turned  medially,  and  this  exposes  the  posterior 
border  of  the  glutaeus  medius  and  the  piriformis.  When  a 
posterior  dislocation  has  occurred,  the  head  of  the  femur  is 
found  between  these  two  muscles. 

Since  the  operation  is  usually  performed  in  children,  the 
epiphysis  of  the  greater  trochanter  is  still  partly  cartilaginous, 
and  this  simplifies  the  next  step,  which  consists  in  turning 
forwards  the  insertion  of  the  glutaeus  medius.  The  oblique 
insertion  of  the  muscle  (p.  416)  is  removed  along  with  its  peri- 
osteum and  a  thin  layer  of  cartilage,  and  the  insertions  of  the 
obturator  internus  and  piriformis  are  treated  in  a  similar  way, 
but  they  are  turned  backwards.  When  these  steps  have  been 
carried  out,  the  trochanteric  fossa,  the  neck  of  the  femur,  the 
head,  if  present,  and  the  remains  of  the  dorsal  aspect  of  the 
capsule  are  all  exposed. 

The  capsule  is  then  split  in  its  long  axis,  and  the  neck  of  the 
femur  is  divided  at  its  distal  end  and  removed.  The  condition 
of  the  acetabulum  and  the  synovial  membrane  can  then  be 
explored  satisfactorily  and  dealt  with.  The  greater  trochanter 
is  brought  to  the  surface  and  is  trimmed  to  fit  the  acetabulum. 
It  is  then  implanted  into  the  latter  at  an  angle  corresponding 
to  that  of  the  original  neck,  and,  in  order  that  this  position  may 
be  maintained,  an  assistant  keeps  the  limb  in  the  required 
degree  of  abduction  until  the  operation  is  completed  and  the 
special  abduction  splint  can  be  applied.  The  remains  of  the 
capsule  and  the  tendons  which  were  removed  are  now  stitched 
together  over  the  trochanter,  and  the  split  glutseus  maximus  is 
sutured.  A  gauze  drain  may  be  passed  down  to  the  neighbour- 
hood of  the  joint,  but  no  tube  is  necessary,  because,  as  the 
acetabulum  is  now  occupied  by  the  trochanter,  there  is  no  space 
to  drain. 

This  operation  aims  at  obtaining  an  ankylosed  and  therefore 
a  stable  joint,  which  is  the  first  essential.  When  the  limb  has 
been  kept  in  a  plaster  case  for  a  year  and  firm  bony  union  has 
occurred,  the  child  is  allowed  to  walk.  In  order  to  bring  the 

28 


434  THE  INFERIOR  EXTREMITY 

limbs  together,  the  pelvis  is  depressed  upon  the  affected  side 
when  the  abducted  limb  is  placed  upon  the  ground,  and  the 
acetabulum  looks  almost  directly  downwards  like  an  inverted 
cup,  thus  ensuring  stability.  Adduction  of  the  sound  limb  is 
necessary,  and  the  centre  of  gravity,  which  is  upset  by  the  tilting 
of  the  pelvis,  is  restored  by  a  compensatory  lumbo-thoracic 
scoliosis.  The  sole  of  the  boot  on  the  sound  limb  may  be 
thickened  to  make  certain  that  the  pelvis  will  be  sufficiently 
tilted,  and  later,  as  the  ankylosed  joint  grows  stronger,  the 
thickening  may  be  gradually  reduced.  Finally,  the  sole  of  the 
boot  on  the  affected  limb  may  be  gradually  thickened,  in  the 
hope  that  the  tilting  of  the  pelvis  will  give  way  to  a  gradual 
angulation  in  the  proximal  part  of  the  femoral  shaft. 

When  excision  of  the  hip-joint  is  performed  in  those  cases 
in  which  the  limb  is  markedly  adducted,  a  preliminary  tenotomy 
of  the  shortened  adductors  is  necessary.  This  enables  the 
limb  to  be  abducted,  and  allows  the  trochanter  to  be  placed 
and  kept  in  the  acetabulum.  Further,  as  the  aim  is  to  obtain 
an  ankylosed  joint  with  the  limb  abducted,  the  adductors  will 
no  longer  be  required.  A  vertical  incision  is  made  along  the 
tendon  of  the  adductor  longus,  and  that  muscle  is  exposed 
together  with  the  gracilis  at  its  medial  border.  Both  are  cut 
across  with  scissors,  and  their  ends  retract,  exposing  the  adductor 
brevis  and  the  anterior  division  of  the  obturator  nerve.  Both 
these  structures  are  divided,  and  the  adductor  magnus,  with  the 
posterior  branch  of  the  obturator  nerve  on  its  surface,  is  brought 
into  view.  The  nerve  is  cut  through  and  the  greater  part  of 
the  muscle  is  divided.  The  wound  is  then  closed,  and  the 
excision  is  performed  in  the  manner  already  described. 

The  Anterior  Route  for  Excision  of  the  Hip-Joint 
is  carried  out  through  a  vertical  incision,  made  dis  tally  from 
the  anterior  superior  iliac  spine,  and  the  skin,  superficial  and 
deep  fasciae  are  divided.  The  sartorius  is  exposed  at  the  medial 
side  of  the  wound,  running  distally  and  medially  (p.  398),  while 
laterally  the  anterior  margin  of  the  tensor  fasciae  latse  is  found. 
The  wound  is  deepened  in  the  V-shaped  interval  between  these 
muscles,  until  the  rectus  femoris  is  brought  into  view.  This 
muscle  is  retracted  medially,  and  at  this  stage  the  ascending 
branch  of  the  lateral  circumflex  (p.  409)  may  be  divided.  The 
anterior  aspect  of  the  capsule  is  then  exposed. 

This  route  may  be  adopted  in  tuberculous  disease  of  the  hip- 
joint  when  there  is  an  abscess  opening  on  the  anterior  aspect  of 


THE  HIP-JOINT  435 

the  limb,  provided  that  a  posterior  dislocation  is  not  present. 
It  may  also  be  utilised  \yhen  operative  interference  is  necessary 
in  congenital  dislocations. 

Attitude  of  the  Lower  Limb  in  Disease  of  the 
Hip-Joint. — Semi-flexion  is  the  position  of  rest  assumed  in  all 
joints.  Consequently  this  is  the  position  which  the  limb  first 
takes  up  when  there  is  effusion  into  the  hip- joint,  since  in  this 
attitude  the  tense  ilio-femoral  ligament  is  relaxed. 

The  commencement  of  tuberculous  disease  in  the  femoral 
neck,  associated  with  a  simple  effusion  into  the  joint,  is  sufficient 
to  cause  flexion  and  slight  lateral  rotation.  When  the  synovial 
membrane  is  attacked  the  thigh  becomes  abducted  in  addition. 
As  a  result  of  the  position  assumed  by  the  limb,  the  pelvis  is 
tilted  downwards  to  the  affected  side  to  enable  the  foot  to  reach 
the  ground,  and  a  compensatory  adduction  of  the  sound  limb 
becomes  necessary  to  restore  the  parallelism  of  the  two  limbs. 
Scoliosis  of  the  lumbo-thoracic  region  restores  the  centre  of 
gravity  (p.  434).  As  a  result  there  is  apparent  lengthening  of 
the  diseased  limb,  but  the  real  condition  is  readily  discovered 
by  measurements  and  the  examination  of  the  relative  positions 
of  the  anterior  superior  iliac  spines. 

As  the  disease  progresses  the  existing  flexion  increases,  and 
the  pelvis  becomes  tilted  forwards  to  accommodate  itself  to  the 
altering  conditions.  To  prevent  the  centre  of  gravity  from  being 
thrown  too  far  forwards  the  lumbar  curve  is  greatly  exaggerated, 
constituting  the  condition  of  lordosis.  At  the  same  time  the 
sound  limb  must  also  take  up  a  flexed  position.  The  inter- 
vertebral  joints  of  the  lumbo-sacral  region  acquire  a  greater 
degree  of  mobility,  and  passive  movements  carried  out  upon 
the  diseased  joint  are  transferred  to  them  at  once  owing  to  the 
rigidity  and  spasm  of  the  surrounding  muscles.  Under  anaesthesia 
and  during  sleep  the  muscles  become  relaxed.  In  the  latter 
case  this  allows  some  movement  between  the  diseased  articular 
surfaces,  and  the  consequent  irritation  of  the  exposed  nerve- 
endings  produces  the  "  starting  pains." 

In  order  to  reduce  the  amount  of  tilting  of  the  pelvis,  com- 
pensation is  sometimes  gained  by  flexing  the  knee  and  extending 
the  ankle  on  the  diseased  side,  so  that  the  patient  walks  on  the 
balls  of  the  toes. 

The  condition  in  which  the  limb  is  flexed,  adducted,  and 
rotated  medially  is  commonly  found  in  tuberculous  disease,  and 
it  is  often  described  as  a  later  stage  of  the  preceding  condition. 


436  THE  INFERIOR  EXTREMITY 

It  seems  possible,  however,  that  in  these  cases  adduction  is 
present  from  the  beginning,  and  that  the  attitude  is  due  to  a 
reflex  stimulation  of  the  adductor  muscles  by  the  obturator 
nerve,  which  helps  to  supply  the  joint  (p.  411).  With  the  thigh 
flexed  and  adducted,  lateral  rotation  would  result  in  the  tighten- 
ing of  the  ilio-femoral  ligament.  The  limb,  therefore,  becomes 
rotated  medially,  and  in  this  position  the  ligament  is  slackened 
to  its  furthest  extent.  As  a  result  of  the  adduction  of  the 
diseased  limb,  the  sound  limb  is  abducted  to  maintain  their 
parallelism,  and  the  pelvis  is  depressed  to  the  sound  side.  This 
necessitates  a  compensatory  scoliosis,  and  the  centre  of  gravity 
takes  up  a  position  over  the  healthy  limb. 

In  this  attitude  the  diseased  limb  appears  to  be  shorter  than 
its  fellow.  If  measurements  show  that  the  shortening  is  real, 
then  either  a  pathological  dislocation  has  occurred  or  the  femoral 
neck  has  been  eroded.  In  both  cases  the  upper  border  of  the 
greater  trochanter  is  found  above  Nelaton's  line  (p.  424). 

When  extension  by  weight  and  pulley  is  used  to  undo  the 
deformity  of  flexion  and  abduction  in  tuberculous  disease  of 
the  hip-joint,  the  force  is  primarily  applied  in  the  long  axis  of 
the  deformed  limb.  As  the  deformity  is  slowly  overcome  the 
pulley  is  gradually  lowered  and  carried  medially.  To  prevent 
the  extending  force  from  simply  increasing  the  downward  tilt 
of  the  pelvis  on  the  affected  side,  a  greater  weight  must  be  applied 
to  the  sound  limb.  A  perineal  band  extending  to  the  top  corner 
of  the  bed  on  the  diseased  side  acts  as  a  fulcrum  over  which  the 
two  weights  pull,  and  the  greater  weight,  being  on  the  sound 
limb,  tends  to  restore  the  pelvis  to  its  normal  position  and,  at 
the  same  time,  to  reduce  the  abduction  of  the  affected  limb. 

When  the  deformity  consists  of  flexion  and  adduction, 
weights  only  need  to  be  applied  to  the  affected  limb,  as  the 
pelvis  is  tilted  upwards  on  that  side.  A  perineal  band  to  the 
top  corner  of  the  bed  on  the  sound  side  is  used  to  provide  a 
fulcrum,  and  the  normal  position  of  the  pelvis  is  gradually 
restored. 

Surgical  Approach  to  the  Neck  of  the  Femur.— The 
region  of  the  greater  trochanter  and  the  neck  of  the  femur  may 
be  approached  either  by  a  vertical  incision  over  the  trochanter 
or  by  a  U-shaped  incision  (p.  415). 

The  vertical  incision  is  carried  through  the  fascial  insertion 
of  the  glutseus  maximus,  exposing  (i)  the  insertion  of  the  glutseus 
medius,  proximally,  (2)  the  postero-distal  part  of  the  trochanter, 


THE  FEMUR  437 

and  (3)  the  tendinous  origin  of  the  vastus  lateralis,  in  the  distal 
part  of  the  wound.  Plastic  operations  on  the  neck  of  the  femur 
(Jones  ;  Murphy)  and  sub-trochanteric  osteotomy  may  be  carried 
out  by  this  route.  The  latter  operation  is  performed  when  the 
hip-joint  is  ankylosed  in  bad  position  and  may  consist  of  the 
removal  of  a  wedge-shaped  portion  or  in  division  of  the  femur. 
When  flexion  constitutes  the  more  marked  deformity,  the 
base  of  the  wedge  is  posterior,  but,  when  adduction  is  more 
pronounced,  the  base  is  on  the  lateral  aspect. 

After  the  femur  has  been  exposed  by  cutting  through  the 
vastus  lateralis,  the  periosteum  is  divided  transversely,  distal 
to  the  greater  trochanter,  and  the  cut  edges  are  elevated  from 
the  bone.  A  wedge  of  bone  may  then  be  removed  from  the 
required  site  and  the  periosteum  is  stitched  together  again. 
When  the  wound  has  been  closed  the  limb  is  placed  in  the 
best  position  obtainable,  and  is  kept  fixed  by  the  necessary 
splints. 

The  Shaft  of  the  Femur  is  so  obscured  by  its  muscular 
covering  that  actual  palpation  is  impossible.  Thickening  of 
the  shaft  may  be  determined  by  grasping  the  thigh  firmly  from 
in  front  so  that  the  finger  tips  are  inserted  along  the  line  of  the 
medial  (or  lateral)  intermuscular  septum,  while  the  thumb  is 
inserted  along  the  line  of  the  lateral  (or  medial)  intermuscular 
septum.  In  comparing  the  circumferential  measurements  of 
the  two  limbs  it  must  be  remembered  that  thickening  of  the 
femoral  shaft  may  be  accompanied  by  atrophy  of  the  surrounding 
muscles,  so  that,  although  the  one  limb  is  normal  and  the  other 
abnormal,  the  measurements  obtained  may  be  practically 
equal. 

In  osteo-myelitis,  incisions  to  expose  the  femoral  diaphysis 
are  made  along  the  line  of  the  lateral  intermuscular  septum,  as 
few  important  structures  intervene  between  the  surface  and 
the  bone  in  this  situation.  The  incision  splits  the  ilio-tibial 
tract  and  exposes  the  vastus  lateralis.  When  the  wound  is 
deepened  through  this  muscle,  the  vastus  intermedius  (crureus) 
is  exposed  and  may  be  elevated  from  the  lateral  surface  of  the 
femur.  If  the  incision  is  extended  over  the  distal  part  of  the 
diaphysis,  the  vastus  lateralis  is  retracted  forwards  from  the 
intermuscular  septum,  which  is  drawn  backwards  together  with 
the  short  head  of  the  biceps.  The  distal  part  of  the  lateral 
surface  of  the  femur  is  thus  exposed,  and  the  anastomosis 
between  the  descending  branch  of  the  lateral  circumflex  and 


438  THE  INFERIOR  EXTREMITY 

the  lateral  superior  genicular  artery  (p.  445)  may  be  seen  on 
the  bone. 

The  distal  part  of  this  incision  may  be  employed  in  performing 
cuneiform  osteotomy  for  genu  varum  (p.  465). 

In  Operations  for  Genu  Valgum  the  distal  portion  of 
the  shaft  is  approached  from  the  medial  side.  The  centre  of 
the  incision  lies  one  finger's  breadth  anterior  and  one  finger's 
breadth  proximal  to  the  adductor  tubercle,  and  the  wound  is 
directed  distally  and  forwards,  parallel  to  the  fibres  of  the 
vastus  medialis.  It  thus  lies  anterior  to  the  articular  branch 
of  the  arteria  genu  suprema  (anastomotica)  and  proximal  to  the 
distal  epiphyseal  cartilage,  which  corresponds  in  level  to  a 
horizontal  line  drawn  through  the  adductor  tubercle.  After 
division  of  the  skin  and  fascise,  the  vastus  medialis  is  split 
and  the  bone  is  exposed.  The  periosteum  is  incised  vertically 
for  about  one  inch,  and  transverse  cuts  are  made  at  each  end  of 
this  incision  so  that  two  small  periosteal  flaps  may  be  elevated. 
Cuneiform  osteotomy  or  partial  division  of  the  femur  may  then 
be  carried  out. 

Fractures  of  the  Proximal  Extremity  of  the 
Femur. — The  neck  of  the  femur  may  be  fractured  (i)  at  its 
proximal  end,  close  to  the  head,  or  (2)  at  its  distal  end,  close  to 
the  greater  trochanter. 

i.  This  fracture  is  common  in  elderly  people  and  is  generally 
due  to  indirect  violence,  but  the  force  required  is  not  great 
owing  to  the  rarefied  condition  of  the  bone.  In  healthy  adults 
the  injury  may  result  from  a  fall  on  the  greater  trochanter  and, 
in  this  case,  the  neck  may  be  impacted  into  the  cancellous  tissue 
of  the  head. 

The  fracture  is  entirely  intra-capsular  and  the  fragments  may 
be  completely  separated  or  they  may  be  retained  in  more  or  less 
accurate  apposition  by  the  periosteum  and  synovial  membrane 
(Fig.  125).  In  old  people  non-union  of  the  fragments  is  very 
common.  It  is  due  partly  to  the  reduced  vitality,  but  especially 
to  the  fact  that  the  blood-supply  to  the  head  from  the  neck  is 
damaged  and  the  supply  via  the  ligamentum  teres  (Fig.  125)  is 
insufficient. 

If  the  neck  is  impacted  into  the  head  the  amount  of 
shortening  is  usually  small  and  special  treatment  is  not  called 
for.  When  shortening  and  eversion  are  pronounced,  active 
measures  must  be  taken  to  obtain  good  alignment,  unless  the 
patient  is  advanced  in  years.  The  older  methods — Liston's 


THE  FEMUR  439 

splint,  and  extension  by  weights,  etc. — have  been  replaced  by 
that  introduced  by  Whitman.  The  limb  is  abducted,  so  that 
the  proximal  fragment  is  forced  against  the  anterior  part  of  the 
capsule  by  the  neck  and  the  broken  surfaces  are  brought  into 
apposition.  The  limit  of  normal  abduction  is  determined  by 
a  comparison  with  the  sound  limb,  and  the  fractured  limb  is 
maintained  in  this  position,  and  with  the  capsule  tense,  by  a 
plaster  case.  When  the  limb  is  adducted  after  union  has 
occurred,  the  head  rotates  upwards,  and  it  is  found  that  there 
is  little  or  no  .shortening. 

2.  Fractures  through  the  distal  part  of  the  neck  of  the  femur, 
although  occasionally  caused  by  indirect  violence,  are  commonly 
due  to  falls  on  the  greater  trochanter.  Owing  to  the  line  of  the 
femoral  attachment  of  the  capsule  (p.  420)  the  fracture  is 
intra-capsular  anteriorly  but  extra- capsular  posteriorly.  When 
the  injury  is  due  to  direct  violence,  the  neck  is  frequently  driven 
into  the  greater  trochanter,  where  it  may  remain  impacted,  or 
the  trochanter  may  be  comminuted.  In  the  latter  condition 
there  is  considerable  widening  of  the  bony  prominence  in  an 
antero-posterior  direction,  and  this  is  more  readily  determined 
owing  to  the  relaxation  of  the  ilio-tibial  tract. 

When  the  fracture  is  not  impacted  there  is  definite  shortening, 
and  the  limb  is  everted,  partly  owing  to  its  weight  and  partly 
owing  to  the  lateral  rotator  muscles,  which  are  much  stronger 
than  the  medial  rotators.  In  impacted  fractures  these  signs ' 
may  be  entirely  lacking  and,  in  addition,  there  may  be  some 
slight  power  of  movement  at  the  joint. 

As  this  variety  of  fracture  usually  occurs  in  healthy  adults, 
good  bony  union  is  generally  obtained,  but  care  must  be  taken 
to  ensure  a  proper  alignment  of  the  limb  and  prevent  shortening. 

Fractures  of  the  Shaft  of  the  Femur.— When  due 
to  indirect  violence  the  fracture  is  usually  oblique  or  spiral,  and 
the  fragments  tend  to  override  one  another.  The  displacement, 
therefore,  is  greater  in  amount  than  it  is  in  fractures  due  to 
direct  violence,  where  the  break  tends  to  be  transverse.  The 
degree  of  displacement  depends  on  the  direction  of  the  causative 
force,  the  action  of  muscles,  and  the  influence  of  gravity. 

In  Fracture  of  the  Proximal  Third  of  the  Shaft  the 
proximal  fragment  becomes  abducted  and  laterally  rotated  by 
the  muscles  attached  to  the  greater  trochanter,  and  it  is  flexed 
by  the  ilio-psoas.  The  amount  of  flexion  is  increased,  as  the 
distal  fragment,  which  is  drawn  proximally  by  the  hamstrings 


440  THE  INFERIOR  EXTREMITY 

and  adductors,  passes  behind  the  proximal  fragment  and  tilts 
it  forwards.  In  addition  the  distal  fragment  becomes  laterally 
rotated  owing  to  the  weight  of  the  foot  and  the  action  of  the 
adductors. 

As  the  proximal  fragment  is  so  short  and  so  deeply  placed, 
it  cannot  be  controlled  easily,  and  the  fracture  is,  therefore, 
very  difficult  to  treat  satisfactorily.  The  distal  fragment  may 
be  brought  into  line  with  the  proximal  fragment  by  putting  the 
limb  up,  flexed  and  abducted,  on  a  double-inclined  plane.  In 
this  position  the  knee  is  passively  flexed  and  the  hamstrings 
are  relaxed.  The  application  of  extension  by  weight  and  pulley 
helps  to  counteract  the  overlapping  of  the  fragments. 

Fractures  in  the  Middle  Third  of  the  Shaft  are  more 
easily  dealt  with  on  account  of  the  greater  length  of  the  proximal 
fragment.  The  displacements  are  due  to  the  same  forces  as 
have  been  described  for  fracture  in  the  proximal  third.  Ex- 
tension by  weight  and  pulley  is  employed  to  counteract  the 
shortening,  and  eversion  of  the  limb  is  prevented  by  maintaining 
the  foot  at  right  angles  to  the  bed. 

When  the  fracture  is  due  to  indirect  violence,  the  extremities 
of  the  fragments  are  sometimes  sharp  and  pointed.  They  may 
become  embedded  in  the  muscles,  and  so  give  rise  to  difficulty 
in  reduction. 

In  infants  this  fracture  is  best  treated  in  the  following  way. 
A  gallows  is  placed  across  the  bed  immediately  above  the  child's 
pelvis.  The  thighs  are  flexed  at  right  angles  to  the  pelvis  and 
the  legs  are  extended  by  weights  and  extension,  acting  over 
pulleys  which  are  fixed  to  the  gallows.  The  weights  used  are 
just  sufficient  to  counterbalance  the  weight  of  the  pelvis  and 
lower  limbs,  which  act  as  the  counterpoise. 

In  Fractures  of  the  Distal  Tljird  of  the  Shaft  (Supra- 
condylar)  the  distal  fragment  is  rotated  backwards  by  the 
gastrocnemius.  At  the  same  time  it  is  drawn  proximally  by 
the  quadriceps  and  hamstrings,  and,  owing  to  the  first  dis- 
placement, it  is  drawn  up  behind  the  proximal  fragment.  A 
double-inclined  plane  is  used  to  relax  the  gastrocnemius,  and 
extension  is  applied  to  counteract  the  shortening,  which  con- 
stitutes the  chief  deformity.  Owing  to  the  small  size  of  the 
distal  fragment,  the  application  of  extension  may  be  a  matter 
of  difficulty.  A  horse-shoe  shaped  stirrup,  which  is  attached 
to  the  distal  fragment  by  sharp  screws,  maintains  satisfactory 
extension  and  has  been  used  with  success. 


THE  REGION  OF  THE  KNEE  441 

The  Posterior  Compartment  of  the  Thigh  contains  the  powerful 
hamstring  muscles,  the  sciatic  nerve  and  its  two  terminal  branches,  the  tibial 
(int.  popliteal)  and  the  common  peroneal  (ext.  popliteal)  nerves. 

The  hamstring  muscles  all  arise  from  the  ischial  tuberosity.  The 
Biceps,  which  passes  distally  and  laterally,  possesses.'  a  second,  or  short 
head  of  origin,  which  arises  from  the  lateral  lip  of  the  linea  aspera.  These 
two  heads  unite  opposite  the  lateral  epicondyle,  and  their  common  tendon, 
which  is  easily  felt  through  the  skin,  extends  to  the  head  of  the  fibula  for  its 
insertion.  The  biceps  flexes  the  knee-joint,  and  is  capable  of  producing  a 
certain  amount  of  lateral  rotation  ;  in  addition,  it  acts  as  an  extensor  of  the 
hip-joint. 

The  Semimembranosus  passes  distally  along  the  medial  side  of  the  posterior 
compartment  of  the  thigh,  and  is  inserted  into  a  groove  on  the  postero-medial 
aspect  of  the  medial  condyle  of  the  tibia.  The  Semitendinosus  is  smaller  in 
bulk  and  lies  on  the  surface  of  the  semimembranosus.  Its  tendon  (p.  443) 
extends  to  the  proximal  part  of  the  medial  surface  of  the  tibia,  where  it  is 
inserted  behind  the  tendons  of  the  gracilis  and  sartorius,  from  which  it  is 
separated  by  a  synovial  bursa  (p.  450).  Like  the  biceps,  both  these  muscles 
extend  the  hip  and  flex  the  knee,  but,  since  they  are  related  to  the  medial 
aspect  of  the  latter  joint,  they  cause  a  slight  amount  of  medial  rotation. 

All  three  muscles  are  supplied  by  the  sciatic  nerve  (L.  4,  5,  S.  i,  2,  and  3), 
but  the  branch  to  the  short  head  of  the  biceps  frequently  arises  from  the 
common  peroneal  nerve  (ext.  popliteal). 

The  Sciatic  Nerve  passes  distally  through  the  posterior 
compartment  of  the  thigh  on  the  posterior  surface  of  the 
adductor  magnus.  Proximally  it  is  crossed  by  the  long  head 
of  the  biceps,  and  in  the  rest  of  its  course  it  is  overlapped  by 
the  semimembranosus.  It  gives  off  branches  of  supply,  which 
enter  the  flexor  muscles  near  their  origin,  and,  together  with 
the  obturator  nerve,  it  supplies  the  adductor  magnus.  In  the 
middle  third  of  the  thigh,  it  ends  by  dividing  into  the  common 
peroneal  (L.  4,  5,  S.  i  and  2)  and  the  tibial  (L.  4,  5,  S.  i,  2,  and 
3)  nerves. 

The  perforating  arteries  from  the  profunda  femoris  (p.  410) 
enter  the  posterior  compartment  of  the  thigh  by  piercing  the 
adductor  magnus  close  to  its  insertion  into  the  linea  aspera. 
They  form  a  longitudinal  series  of  anastomoses  with  one  another. 
Proximally  the  first  perforating  artery  takes  part  in  the  crucial 
anastomosis  (p.  418) ;  distally,  the  third  and  fourth  perforating 
arteries  anastomose  with  the  proximal  muscular  branches  of 
the  popliteal  (p.  445). 


THE    REGION    OF   THE    KNEE. 

Surface   Landmarks. — As  there  is  little  elasticity  in  the 
ligamentum  patellae,  the  patella  remains  at  a  constant  distance 


442 


THE  INFERIOR  EXTREMITY 


from  the  tibial  tuberosity,  whether  the  knee-joint  is  flexed  or 
extended.  In  extension  of  the  knee-joint,  the  distal  part  of 
the  articular  surface  of  the  patella  is  in  contact  with  the 
proximal  part  of  the  trochlea  (Fig.  131),  but,,  when  the  joint  is 
flexed,  the  patella  is  drawn  downwards  by  its  ligament  so  that 
its  articular  surface  is  more  fully  in  contact  with  the  femur. 


Vastus  lateral 

\      \  I 

"V  astus  medialis 
Quadriceps  tendon 
Adductor  tubercle 


Depression  over  latera 
meniscus' 


Head  of  fibula 


Depression  over  medial 
meniscus 

Ligamentum  patellae 


Tibial  tuberosity 


FIG.  127. — Surface  Landmarks  in  the  Region  of  the  Knee. 

When  the  knee  is  passively  extended  the  patella  may  be 
moved  from  side  to  side,  and,  owing  to  the  elasticity  of  the 
quadriceps  muscle,  it  may  be  pushed  distally.  When  the  joint 
is  distended  with  fluid  the  articular  surfaces  of  the  patella 
and  the  femur  are  separated  from  one  another.  This  condition 
is  termed  "  floating  patella,"  and,  when  the  patella  is  gently 
tapped,  it  may  be  made  to  knock  against  the  femur. 

The  ligamentum  patella  can  be  traced  from  the  apex  of  the 
patella  to  the  tibial  tuberosity.     It  is  about  two  inches  long  and 


THE  REGION  OF  THE  KNEE  443 

its  mid-point  corresponds  to  the  level  of  the  knee-joint.  On 
each  side  of  the  ligamentum  patellae  a  slight  triangular  depression 
can  be  seen  when  the  knee  is  semi-flexed.  The  lateral  depression 
is  bounded  distally  by  the  anterior  margin  of  the  proximal 
extremity  of  the  tibia,  laterally  by  the  margin  of  the  articular 
surface  of  the  femur ,  and  medially  by  the  ligamentum  patellae. 

The  medial  depression  is  bounded  by  the  corresponding 
parts  of  the  femur,  tibia,  and  patellar  ligament.  Palpation 
of  the  collateral  boundaries  of  these  depressions  readily  reveals 
the  presence  of  lipping  of  the  femoral  condyles  in  rheumatoid 
arthritis.  Aspiration  of  the  knee-joint  may  be  carried  out 
through  either  of  these  areas,  but  when  the  joint  is  distended 
with  fluid,  the  surface  depressions  are  no  longer  visible. 

The  tibial  tuberosity  (tubercle)  can  easily  be  palpated ;  it 
lies  one  inch  distal  to  the  line  of  the  knee-joint.  The  head  of  the 
fibula  is  placed  on  the  same  level  as  the  tibial  tuberosity,  but  on 
a  plane  posterior  to  it.  It  serves  as  a  guide  to  the  common 
peroneal  (ext.  popliteal)  nerve,  which  can  be  rolled  against  the 
bone  as  it  crosses  the  lateral  aspect  of  the  fibular  neck. 

The  lateral  aspect  of  the  lateral  condyle  and  the  medial 
aspect  of  the  medial  condyle  of  the  femur  are  both  subcutaneous. 
The  adductor  tubercle  is  the  most  proximal  palpable  point  on  the 
medial  condyle,  and  when  the  knee  is  semi-flexed  the  tendon  of 
the  adductor  magnus  can  be  traced  proximally  from  it. 

In  active  extension  of  the  knee-joint  the  tendon  of  the 
rectus  femoris  forms  a  tense  band,  ij  inches  wide,  which  is 
inserted  into  the  proximal  border  of  the  patella.  In  the  same 
position  of  the  limb  the  vastus  medialis  forms  a  prominent 
elevation  to  the  medial  side  of  the  tendon,  and  the  vastus  lateralis 
forms  a  similar  elevation  on  the  lateral  side  but  it  is  placed  at  a 
more  proximal  level.  A  very  definite  depression  lies  immediately 
distal  to  the  elevation  produced  by  the  vastus  lateralis  ;  it  is 
bounded  medially  by  the  rectus  femoris  and  laterally  by  the 
ilio-tibial  tract.  The  latter  forms  a  distinct  ridge,  which  crosses 
the  antero-lateral  aspect  of  the  joint  and  can  be  traced  distally 
to  its  attachments  on  the  lateral  condyle  of  the  tibia  and  the 
head  of  the  fibula. 

When  the  knee  is  flexed  against  resistance,  the  tendons  of 
the  hamstrings  are  rendered  prominent  and  can  be  palpated 
almost  to  their  respective  insertions.  The  tendon  of  the  semi- 
membranosus  is  felt  on  the  medial  side  of  the  tendon  of  the 
semitendinosus ,  which,  however,  is  more  superficial.  On  the 


444 


THE  INFERIOR  EXTREMITY 


lateral  aspect  of  the  distal  part  of  the  thigh,  the  fingers  can  be 
made  to  sink  into  the  popliteal  fossa,  through  the  interval  which 
is  bounded  behind  by  the  biceps  tendon  and  in  front  by  the 
ilio-tibial  tract.  A  similar  interval  can  be  made  out  on  the 
medial  side  behind  the  tendon  of  the  adductor  magnus. 

The  Popliteal  Fossa  lies  behind  the  knee-joint  and  extends 
beyond  it  in  both  directions.  Its  roof,  which  is  formed  by  a 
thin  but  strong  sheet  of  deep  fascia,  is  pierced  near  its  centre 


Adductor  magnus 
tendon 

Vastus  medialis 


Popliteal  fossa 
Semimembranosus 

Medial  condyle  of  femur 
-  Semitendinosus 


FIG.  128.— The  Medial  Side  of  the  Knee. 

by  the  small  saphenous  vein.  Proximally,  the  fossa  is  bounded 
by  the  biceps  on  the  lateral  side,  and  by  the  semimembranosus 
and  semitendinosus  on  the  medial  side  ;  distally,  it  is  bounded 
by  the  two  heads  of  origin  of  the  gastrocnemius.  The  floor  of 
the  fossa  is  formed  by  the  popliteal  surface  of  the  femur,  the 
posterior  ligament  of  the  knee-joint,  and  the  posterior  surface 
of  the  popliteus,  which  is  covered  by  a  strong  layer  of  fascia. 

The  Popliteal  Artery  begins  at  the  hiatus  tendineus  in 
the  adductor  magnus  (p.  412),  where  it  is  continuous  with  the 
femoral  artery.  As  it  passes  through  the  popliteal  fossa  it 
inclines  laterally  till  it  reaches  the  middle  line  of  the  limb,  and 
then  descends  vertically  to  the  distal  border  of  the  popliteus, 


THE  REGION  OF  THE  KNEE  445 

where  it  terminates  by  dividing  into  the  anterior  and  posterior 
tibial  arteries.  Throughout  its  course  the  artery  is  very  deeply 
placed,  and  it  lies  in  direct  contact  with  the  posterior  ligament 
of  the  knee-joint.  , 

Ligature  of  the  Popliteal  Artery  may  be  carried  out  for 
aneurism,  or  following  wounds  of  the  vessel.  The  incision  lies 
behind  and  parallel  to  the  tendon  of  the  adductor  magnus, 
and  when  the  skin  is  divided,  the  great  saphenous  vein  and  the 
saphenous  nerve  are  exposed.  These  structures  are  retracted 
backwards  together  with  the  sartorius,  which  is  seen  when  the 
deep  fascia  is  incised  (Fig.  128).  The  wound  is  then  deepened 
between  the  adductor  magnus  and  the  semimembranosus. 
Flexion  of  the  knee  relaxes  the  latter  muscle  and  enables  it  to 
be  retracted  so  as  to  permit  the  finger  to  be  inserted  into  the 
fat  which  intervenes  between  the  popliteal  artery  and  the  femur. 
The  sheath  of  the  vessel  is  carefully  incised  on  its  medial  aspect,, 
and  the  popliteal  vein  and  the  tibial  nerve,  which  lie  on  its 
postero-lateral  side,  are  thus  avoided. 

The  Branches  of  the  Popliteal  Artery  can  be  divided  into  three  groups  : 
(a)  muscular,  (b)  cutaneous,  (c)  articular,  (a)  The  proximal  muscular  branches 
supply  the  hamstrings  and  anastomose  with  the  perforating  arteries  (p.  410); 
the  distal  muscular  branches  are  distributed  to  the  muscles  of  the  calf,  (b) 
The  cutaneous  branch  supplies  the  skin  of  the  calf,  and  is  accompanied  by  the 
medial  cutaneous  branch  of  the  tibial  nerve,  (c)  The  articular  branches  are 
five  in  number  : 

1.  The  middle  genicular  (azygos)  artery  enters  the  knee-joint  by  piercing 
the  posterior  ligament,  and  is  distributed  to  the  structures  within  the  capsule. 

2.  The  superior  genicular  arteries,  lateral  and  medial,  wind  round  the 
femur,  proximal  to  the  condyles.    They  are  in  close  contact  with  the  bone, 
and  anastomose  with  one  another  anteriorly.     In  addition,  they  anastomose 
with  the  inferior  genicular  arteries,  and  with  the  descending  branch  of  the 
lateral   circumflex  and  the  articular  branch  of  the  arteria  genu  suprema 
(p-  4I3)-    The  latter  anastomosis  helps  to  re-establish  the  circulation  in  the 
leg  when  the  popliteal  artery  is  ligatured  in  its  proximal  part. 

3.  The  inferior  genicular  arteries,  lateral  and  medial,  wind  round  to  the 
anterior  aspect  of  the  knee.     In  their  course  they  pass  under  cover  of  the 
tibial  and  fibular  collateral  (internal  and  external  lateral)  ligaments  respec- 
tively, and  they  anastomose  with  one  another  under  cover  of  the  ligamentum 
patellae.    They  communicate  with  the  superior  genicular  arteries,  and  so 
take  part  in  the  important  anastomosis  around  the  knee-joint. 

The  Tibial  (Internal  Popliteal)  Nerve  (L.  4,  5,  S.  i, 

2,  3)  arises  from  the  sciatic  in  the  posterior  compartment  of 
the  thigh  and  extends  distally  in  the  middle  line  of  the  limb. 
In  the  popliteal  fossa  it  lies  superficial  to  the  popliteal  vessels 
and  it  crosses  them  obliquely  from  the  lateral  to  the  medial  side. 
At  the  distal  border  of  the  popliteus  the  tibial  nerve  passes 


446  THE  INFERIOR  EXTREMITY 

deep  to  the  soleus  and  enters  the  posterior  compartment  of  the 
leg. 

As  it  traverses  the  popliteal  fossa,  the  tibial  nerve  gives  off 
(a)  muscular,  (b)  cutaneous,  and  (c)  articular  branches.  The 
muscular  branches  supply  both  heads  of  the  gastrocnemius,  the 
soleus,  the  plantaris,  and  the  popliteus.  The  cutaneous  branch 
is  termed  the  medial  cutaneous  nerve  of  the  calf  (ramus 
communicans  tibialis).  It  descends  between  the  two  heads  of 
the  gastrocnemius  and  unites  with  the  peroneal  anastomotic 
nerve  (r.  communicans  fibularis)  to  form  the  nervus  suralis 
(external  saphenous)  (S.  i  and  2)  (p.  473).  The  articular  twigs, 
three  in  number,  supply  the  knee-joint. 

The  Common  Peroneal  (Ext.  Popliteal)  Nerve  (L.  4, 
5,  S.  i,  2)  passes  distally  and  laterally  in  close  relation  to  the 
medial  aspect  of  the  biceps  tendon,  and  leaves  the  popliteal 
fossa  in  the  interval  between  the  tendon  and  the  lateral  head 
of  the  gastrocnemius.  It  then  descends  behind  the  head  of 
the  fibula  and  winds  round  the  lateral  aspect  of  the  fibular 
neck,  piercing  the  origin  of  the  peronaeus  longus.  In  this 
situation  the  nerve  ends  by  dividing  into  the  superficial  and 
deep  peroneal  nerves  (musculo-cutaneous  and  anterior  tibial) 
(L.  4,  5,  S.  i). 

The  common  peroneal  nerve  gives  off  no  muscular  branches, 
but  it  supplies  articular  twigs  to  the  knee-joint  and  gives  origin 
to  the  lateral  sural  nerve  (L.  4,  5,  S.  i),  which  supplies  the  skin 
over  the  proximal  part  of  the  tibialis  anterior,  and  the  peroneal 
anastomotic  nerve,  which  helps  to  form  the  nervus  suralis. 

The  Popliteal  Lymph  Glands  are  divided 'into  a  superficial 
and  a  deep  group.  The  superficial  lymph  glands  surround  the 
small  saphenous  vein  as  it  pierces  the  deep  fascia.  They  receive 
aflerents  from  the  lateral  aspect  of  the  foot  and  leg,  and  their 
efferents  open  into  the  deep  group. 

The  deep  lymph  glands  are  embedded  in  the  fat  which 
surrounds  the  popliteal  vessels.  They  receive  the  efferents 
of  the  superficial  group,  and,  in  addition,  most  of  the  numerous 
lymph  vessels  from  the  deep  tissues  of  the  calf  and  the  sole  of 
the  foot.  The  remainder  of  the  latter  pass  direct  to  the  deep 
subinguinal  lymph  glands  (p.  400).  The  efferents  of  the  deep 
popliteal  lymph  glands  terminate  in  the  deep  subinguinal 
group. 

Abscesses  arising  in  these  lymph  glands  follow  some  septic 
infection  of  the  leg  or  toes.  Owing  to  the  depth  at  which  the 


THE  REGION  OF  THE  KNEE  447 

pus  lies  from  the  surface,  its  presence  is  difficult  to  determine 
at  an  early  stage,  but  early  diagnosis  is  necessary,  as  when 
evacuation  is  delayed  the  abscess  cavity  takes  a  long  time  to 
granulate  up.  This  slow  closure  is  partly  due  to  the  rigid  walls 
of  the  cavity,  which  are  formed  by  the  hamstring  tendons,  and 
partly  to  the  destruction  of  the  fat  in  which  the  lymph  glands 
are  embedded. 

Abscesses  in  the  popliteal  fossa  are  best  approached  from 
the  lateral  aspect  of  the  knee.  An  incision  is  made  behind  the 
lateral  intermuscular  septum  (p.  402),  but  in  front  of  the  biceps 
tendon.  When  the  deep  fascia  is  divided,  a  pair  of  dressing 
forceps  can  be  passed  medially  between  the  biceps  and  the 
femur,  and  the  pus  is  evacuated  by  Hilton's  method  in  order  to 
avoid  injuring  the  large  vessels  and  nerves. 

The  Popliteus  Muscle  arises  within  the  capsule  of  the  knee-joint  from 
the  lateral  aspect  of  the  lateral  femoral  condyle.  It  passes  distally  and 
medially  across  the  joint,  and  is  inserted  into  the  proximal  part  of  the  posterior 
surface  of  the  tibia.  Near  its  origin  the  popliteus  intervenes  between  the 
lateral  meniscus  (semilunar  cartilage)  and  the  fibular  collateral  ligament  (p. 
455).  It  is  supplied  by  the  tibial  (int.  popliteal)  nerve  (L.  4,  5,  and  S.  i) 
and  acts  as  a  flexor  of  the  knee-joint.  In  addition,  when  the  tibia  is  fixed 
the  popliteus  acts  as  a  lateral  rotator  of  the  femur,  and  when  the  tibia  is  free 
to  move  it  acts  as  a  medial  rotator  of  the  tibia. 

Superficial  Veins  of  the  Lower  Limb. — A  venous  arch 
extends  across  the  dorsum  of  the  foot  near  the  heads  of  the 
metatarsal  bones.  It  is  continued  backwards  along  the  medial 
border  of  the  foot  as  the  great  saphenous  vein,  which  ascends  in 
front  of  the  medial  malleolus  and  then  along  the  medial  border 
of  the  tibia  to  the  medial  side  of  the  knee-joint.  The  remainder 
of  its  course  may  be  indicated  by  a  line  joining  the  adductor 
tubercle  to  the  fossa  ovalis  (p.  401).  At  the  latter  point  the 
great  saphenous  vein  passes  through  the  deep  fascia  and  joins 
the  femoral  vein. 

The  small  saphenous  vein  arises  at  the  lateral  extremity  of 
the  dorsal  venous  arch  and  passes  backwards  along  the  lateral 
border  of  the  foot.  From  behind  the  lateral  malleolus  it 
ascends  obliquely  in  the  superficial  fascia  of  the  back  of  the 
leg,  and  near  the  centre  of  the  popliteal  fossa  it  pierces  the 
fascial  roof  to  join  the  popliteal  vein.  It  usually  communicates 
with  the  great  saphenous  by  a  branch  which  winds  round  the 
postero-medial  aspect  of  the  knee,  or  by  one  which  arises  at  a 
lower  level  and  crosses  in  front  of  the  proximal  part  of  the  tibia. 

Except  for  a  short  distance  from  their  termination,  both 
saphenous  veins  lie  in  the  superficial  fascia  and1  therefore 


448  THE  INFERIOR  EXTREMITY 

receive  no  muscular  support.  Owing  to  this  lack  of  support 
and  to  the  action  of  gravity,  these  veins  are  very  liable  to 
become  varicose.  Both  veins  contain  numerous  valves,  which 
help  to  support  the  column  of  blood.  The  rupture  of  one  of 
these  valves  increases  the  strain  on  the  one  distal  to  it,  which 
in  turn  gives  way.  The  unsupported  vessel  walls  are  not  strong 
enough  to  support  the  column  of  blood  when  the  patient  is  in 
the  erect  attitude,  and  they  consequently  become  dilated  and 
varicose.  The  middle  third  of  the  great  saphenous  vein  is  most 
frequently  affected,  but  its  proximal  and  distal  parts  and  the 
small  saphenous  vein  are  often  involved. 

When  the  patient  adopts  the  recumbent  posture,  the  veins, 
though  varicose,  are  able  to  fulfil  their  function,  and  in  conse- 
quence, elastic  bandages,  stockings,  etc.,  which  are  used  as  a 
mechanical  support,  should  be  applied  before  the  patient  rises 
from  this  posture. 

Owing  to  the  obstruction  to  the  venous  return  the  vitality 
of  the  skin  is  diminished,  especially  in  the  distal  part  of  the 
limb,  and  chronic  ulceration  tends  to  arise  after  trivial  injuries 
in  this  region.  Healing  is  always  tedious  and  may  not  occur 
unless  the  patient  is  kept  in  bed  with  the  limb  slightly  elevated. 
This  position  assists  the  venous  return,  and  so  improves  the 
vitality  of  the  affected  part. 

The  Bursae  around  the  Knee.— Numerous  bursse,  some 
of  which  communicate  with  the  interior  of  the  joint,  lie  in 
relation  to  the  tendons  around  the  knee. 

Anterior. — (i)  The  supra-patellar  bursa  almost  invariably 
communicates  with  the  joint.  It  lies  behind  the  tendon  of 
the  quadriceps  and  is  separated  from  the  femoral  diaphysis  by 
an  extra-synovial  pad  of  fat  (Fig.  131).  It  extends  upwards 
for  a  hand-breadth  above  the  proximal  border  of  the  patella, 
and  is  outlined  in  hydrops  of  the  joint.  Fluid  may  be  aspirated 
from  the  knee-joint  through  this  bursa. 

(2)  The  prepatellar  bursa  is  subcutaneous  and  lies  in  front 
of  the  distal  part  of  the  patella  and  the  proximal  part  of  the 
ligamentum  patellae.  When  the  bursa  is  exposed  to  much 
pressure,  effusion  is  apt  to  occur  into  it  and  the  condition  may 
become  chronic,  with  the  formation  of  fibrous  bands  and  "  melon- 
seed  "  bodies  ("  housemaid's  knee  ").  The  prepatellar  bursa, 
when  thus  affected,  may  be  removed  through  a  semilunar 
incision,  the  base  of  which  is  distal,  so  that  pressure  on  the  scar 
is  subsequently  avoided. 


THE  REGION  OF  THE  KNEE  449 

When  enlarged,  this  bursa  projects  beyond  the  margins  of 
the  ligamentum  patellae,,  and  so  is  brought  into  close  relationship 
with  the  capsule  of  the  joint.  In  acute  suppurative  conditions,, 
therefore,  it  is  important  that  the  bursa  should  be  incised  and 
drained  at  an  early  stage  to  prevent  the  joint  from  becoming 
infected.  An  incision  is  made  on  each  side  of  the  middle  line 
so  that  the  bursa  may  be  thoroughly  drained. 

(3)  A  small  subcutaneous  bursa  is  sometimes  present  in  front 
of  the  tibial  tuberosity  and  the  distal  part  of  the  ligamentum 
patellae. 

(4)  The  infra-patellar  bursa  is  placed  between  the  proximal 
extremity  of  the  tibia  and  the  deep  surface  of  the  ligamentum 
patellae.     It  is  only  separated  from  the  synovial  lining  of  the 
joint  by  the  infra-patellar  pad  of  fat.    When  effusion  takes 
place  into  this  bursa,  there  is  slight  fulness  on  each  side  of  the 
ligament  near  the  tibial  tuberosity,  and  full  flexion  causes  pain 
in  this  region. 

Postero- Lateral. — (i)  A  bursa  is  situated  between  the 
lateral  head  of  the  gastrocnemius  and  the  capsule  covering  the 
lateral  femoral  condyle ;  it  sometimes  communicates  with  the 
cavity  of  the  knee-joint. 

(2)  A  small  bursa  is  usually  interposed  between  the  biceps 
tendon  and  the  fibular  collateral  (external  lateral)  ligament  of 
the  knee. 

(3)  A  protrusion  of  the  synovial  lining  of  the  knee-joint 
separates  the  tendon  of  the  popliteus  from  the  lateral  condyle.    It 
varies  in  extent,  sometimes  forming  a  complete  sheath  for  the 
tendon  and  communicating  distally  with  the  cavity  of  the 
proximal  tibio-fibular  joint  (p.  460). 

(4)  A  small  bursa  separates  the  popliteus  tendon  from  the 
fibular  collateral  ligament.    It  may  be  incorporated  with  the 
preceding  bursa,  when  the  latter  is  of  large  size. 

Postero-Medial. — (i)  A  bursa  is  placed  between  the  medial 
head  of  the  gastrocnemius  and  the  capsule  covering  the  medial 
femoral  condyle.  It  is  frequently  in  communication  with  the 
knee-joint. 

(2)  A  bursa,  which  frequently  communicates  with  the 
preceding,  is  situated  between  the  medial  head  of  the  gastrocnemius 
and  the  semimembranosus  tendon. 

Gradual  enlargement  of  these  bursse,  accompanied  by  pain 
and  limitation  of  movement  at  the  knee-joint,  is  sometimes  met 
with  in  gamekeepers  and  shepherds.  This  is  said  to  be  due 

29 


450 


THE  INFERIOR  EXTREMITY 


to  the  increased  amount  of  flexion  at  the  knee-joint  which 
is  necessary  when  walking  through  heather  and  gorse.  The 
swelling  usually  enlarges  distally  in  an  intermuscular  interval 
and  assumes  a  sausage -shape.  Such  swellings  have  been 


FIG.  129. — Normal  Knee-joint  of  a  Child,  aged  four.     Antero-posterior  view. 
The  centre  of  ossification  for  the  head  of  the  fibula  is  not  yet  present. 

mistaken  for  varicose  veins,  and  they  are  usually  much  larger 
than  they  appear  to  be,  since  they  lie  under  the  deep  fascia. 

(3)  The  tendons  of  the  sartorius,  gracilis,  and  semitendinosus 
are  separated  from  one  another  at  their  insertions,  and  from 
the  tibial  collateral  (internal  lateral)  ligament  by  one  or  more 
bursse. 


THE  REGION  OF  THE  KNEE  451 

Ossification  of  the  Distal  Extremity  of  the  Femur.— A 

secondary  centre  appears  in  the  cartilaginous  distal  extremity 
of  the  femur  during  the  ninth  month  of  fcetal  life.  It  is  the 
earliest  secondary  centre  to  appear,  and  following  the  general 


FIG.  130. — Knee-joint  of  Child,  aged  thirteen.  Lateral  view.  Observe  the 
epiphyseal  lines  on  the  tibia  and  fibula.  A  separate  centre  of  ossification 
is  present  for  the  tibial  tuberosity.  Note  also  the  position  of  the  head 
of  the  fibula. 

rule  that  epiphyses  which  ossify  early  unite  late,  it  does  not 
join  the  diaphysis  till  the  twenty-first  year.  Growth  in  length, 
therefore,  proceeds  for  a  longer  period  at  the  distal  than  at  the 
proximal  extremity  of  the  femur  (p.  420).  The  distal  epiphyseal 
line  corresponds,  anteriorly,  to  the  proximal  border  of  the 
articular  surface,  and  posteriorly,  to  the  intercondylar  line. 

29  a 


452  THE  INFERIOR  EXTREMITY 

On  the  condyles  the  line  is  curved  with  a  downward  convexity, 
and  on  the  medial  side  it  passes  through  the  adductor  tubercle. 

Ossification  of  the  Proximal  Extremity  of  the  Tibia.— 
A  secondary  centre  appears  in  the  cartilaginous  proximal 
extremity  of  the  tibia  shortly  before  birth,  and  the  epiphysis 
which  it  forms  includes  both  condyles  and  the  tibial  tuberosity. 
Occasionally  the  tibial  tuberosity  possesses  a  separate  centre 
of  ossification,  which  appears  at  the  eleventh  or  twelfth  year 
and  soon  fuses  with  the  rest  of  the  epiphysis.  The  proximal 
epiphysis  of  the  tibia  unites  with  the  shaft  at  about  the  twenty- 
fourth  year.  The  epiphyseal  line  usually  passes  through  the 
articular  surface  for  the  head  of  the  fibula. 

The  Patella  does  not  begin  to  ossify  till  the  third  year,  but 
ossification  is  complete  at  puberty. 

The  Knee -Joint. — The  Capsule  of  the  knee-joint  is 
strongest  on  the  posterior  aspect  of  the  joint,  and  it  is  quite 
distinct  on  the  lateral  and  medial  aspects.  Anteriorly  it  forms 
a  thin  fibrous  layer  closely  applied  to  the  outer  surface  of  the 
synovial  membrane,  but,  proximal  to  the  patella  and  over  the 
area  occupied  by  the  patella,  it  is  entirely  deficient.  On  each 
side  of  the  patella  the  capsule  depends  for  its  strength  on 
the  tendinous  expansions  of  the  vasti,  lateralis  and  medialis 
(p.  409). 

Proximally,  the  line  of  attachment  of  the  capsule  crosses  the 
epiphyseal  line  on  the  lateral  and  medial  condyles,  but  it  remains 
at  least  half  an  inch  distant  from  the  margins  of  the  articular 
surface.  Posteriorly  the  capsule  is  attached  to  the  proximal 
margins  of  the  articular  surfaces  and  to  the  intercondylar  line. 
On  this  aspect,  therefore,  the  line  of  attachment  of  the  capsule 
practically  coincides  with  the  epiphyseal  line. 

Distally,  the  capsule  is  attached  to  the  tibial  condyles,  a 
little  beyond  the  margins  of  the  articular  surface. 

The  Synovial  Membrane  of  the  knee-joint  is  very  extensive, 
and  its  arrangement  is  complicated  by  the  presence  of  the 
intra-articular  ligaments  and  menisci.  It  lines  the  deep  aspect 
of  the  capsule,  from  which  it  is  reflected  on  to  those  parts  of  the 
femur  and  tibia  which  are  intra-capsular  but  non-articular. 
From  the  antero-distal  part  of  the  joint  a  triangular  fold  of 
the  synovial  membrane  passes  proximally  and  backwards,  to 
be  attached  by  its  apex  to  the  anterior  extremity  of  the  inter- 
condylar fossa.  This  fold  is  termed  the  patellar  synovial  fold 
(ligamentum  mucosum),  and  its  free  margins  are  known  as  the 


THE  REGION  OF  THE  KNEE 


453 


alar  folds  (ligamenta  alarm).  An  extra-synovial  but  intra- 
capsular  pad  of  fat  lies  behind  the  ligamentum  patellae,,  and  the 
portion  of  it  which  is  carried  in  between  the  two  layers  of  the 
patellar  synovial  fold  (Fig.  131)  is  frequently  the  site  of  hyper- 
trophy (lipoma  arborescens).  In  this  condition  grape -like 
pieces  may  become  detached  and  constitute  loose  bodies  within 


Supra-patellar  bursa 
Quadriceps  tendon 


Distal  epiphyseal  line 

of  femur 

Anterior  cruciate  lig. 

Oblique  popliteal  lig. 


Proximal  epiphysea 
line  of  tibia 


Prepatellar  bursa 


Infra-patellar  pad  of  fat 
atellar  synovial  fold 
^Ligamentum  patellae 

Deep  infra-patellar  bursa 

Subcutaneous  infra-patellar 
bursa 


FIG.  131. — Sagittal  Section  through  the  Knee-joint. 

Light  blue  =  articular  cartilage.  Green  —  periosteum. 

Striped  blue  =  tendons  and  ligaments.          Red  =  synovial  membrane. 

the  joint.     Similar  hypertrophy  may  affect  the  pad  of  fat  which 
intervenes   between  the  femur  and  the  supra-patellar  bursa 

(Fig.  131). 

Both  the  femoral  and  the  tibial  surfaces  of  the  menisci 
(semilunar  cartilages)  are  covered  by  the  synovial  membrane 
(Fig.  132)  which  helps  to  attach  their  peripheral  margins  to 
the  tibia  (coronary  ligaments). 

In  the  posterior  part  of  the  joint  the  synovial  membrane  is 
drawn  off  the  central  part  of  the  posterior  ligament  by  the 

29  & 


454 


THE  INFERIOR  EXTREMITY 


posterior  cruciate  ligament.  It  covers  both  cruciate  ligaments 
anteriorly  and  on  each  side,  so  as  to  render  them  extra-synovial. 

Protrusions  of  the  synovial  membrane  escape  from  the 
capsule  to  form  the  supra  -  patellar  and  the  popliteus  bursse 
(p.  449). 

The    Ligamentum    Patellae  (p.  441)  serves  to  strengthen 


Distal  epi- 
physis  of  femur 
Tibial 
collateral 
ligament 
Anterior 
.  cruciate 
ligament 

Medial  meniscus 


Proximal  epiphysis 
of  tibia 


Lateral  meniscus 
Tendon  of  popliteus 

Popliteus  bursa 

Fibular  collateral 
ligament 

Proximal  tibio- 
fibular  joint 

Head  of  fibula         , 

* 


FIG.  132. — Oblique  Section  through  the  Right  Knee-joint. 

Light  blue  =  articular  cartilage.  Green  —  periosteum. 

Striped  blue  =  ligaments  and  menisci.          Red  =  synovial  membrane. 

the  capsule  anteriorly  and  takes  the  place  of  an  anterior  ligament 
of  the  knee-joint. 

The  Tibial  Collateral  (Internal  Lateral)  Ligament  is  a 
broad  flattened  band  which  strengthens  the  capsule  on  its 
medial  aspect.  Proximally  it  is  attached  to  the  femur  near 
the  adductor  tubercle.  It  crosses  the  medial  aspect  of  the 
joint  and  is  firmly  adherent  to  the  peripheral  border  of  the  medial 


THE  REGION  OF  THE  KNEE  455 

meniscus  (p.  456).  Distally,  the  tibial  collateral  ligament  extends 
to  the  proximal  part  of  the  shaft  of  the  tibia,  where  it  receives 
attachment  behind  the  semitendinosus  tendon. 

The  Fibular  Collateral  (External  Lateral)  Ligament 
forms  a  distinct  rounded  band,  which  is  attached  to  the  lateral 
condyle  of  the  femur  about  half  an  inch  from  its  articular 
margin.  As  it  crosses  the  lateral  aspect  of  the  knee-joint,  the 
ligament  is  separated  from  the  lateral  meniscus  by  the  popliteus 
tendon,  its  associated  bursa  (p.  456),  and  the  lateral  inferior 
genicular  artery.  Distally,  it  is  attached  to  the  head  of  the 
fibula  in  close  relation  to  the  insertion  of  the  biceps. 

The  collateral  ligaments  may  be  strained  or  torn  during  the 
same  violent  movements  of  the  joint  which  may  give  rise  to 
injury  of  the  menisci.  In  the  former  condition  tenderness  is 
experienced  on  palpation  over  the  injured  ligament,  whereas, 
when  the  menisci  are  involved,  the  tenderness  is  most  marked 
in  the  triangular  depressions  at  the  sides  of  the  ligamentum 
patellae  (p.  443). 

The  Posterior  part  of  the  capsule  is  specially  thickened 
and  helps  the  anterior  cruciate  ligament  to  prevent  hyper- 
extension  of  the  joint.  It  is  further  strengthened  by  the  oblique 
popliteal  ligament,  which  extends  obliquely  across  the  back  of 
the  joint  from  the  semimembranosus,  at  its  insertion,  to  the 
medial  border  of  the  lateral  femoral  condyle. 

The  Medial  Meniscus  (Int.  Semilunar  Cartilage)  of  the 
knee-joint  is  interposed  between  the  peripheral  parts  of  the 
medial  condyles  of  the  tibia  and  the  femur.  It  is  semilunar  in 
outline,  and  its  two  extremities  are  widely  separated  from  one 
another.  The  anterior  extremity  is  attached  to  the  anterior 
part  of  the  non-articular  area  on  the  top  of  the  tibia,  and  in 
addition  it  is  connected  to  the  anterior  part  of  the  lateral 
meniscus  by  the  transverse  ligament.  The  posterior  extremity 
is  attached  to  the  posterior  part  of  the  non-articular  area  referred 
to  above  (Fig.  133). 

The  Lateral  Meniscus  (External  Semilunar  Cartilage)  is 
nearly  circular  in  outline,  and  its  extremities  are  attached  close 
to  one  another.  Its  anterior  extremity  is  attached  to  the  tibia 
immediately  in  front  of  the  intercondylar  eminence  (tibial  spine), 
while  its  posterior  extremity  is  attached  to  the  eminence  itself, 
and  is  also  connected  with  the  posterior  cruciate  ligament 
(Fig.  133). 

The  menisci  are  thickest  round  their  peripheral  borders  and 

29  c 


456 


THE  INFERIOR  EXTREMITY 


thin  away  to  their  free  central  margins.  The  peripheral  border 
of  the  medial  meniscus  is  firmly  adherent  to  the  tibial  collateral 
ligament,  but  the  fibular  collateral  ligament  is  separated  from 
the  lateral  meniscus  by  the  popliteus  tendon,  its  synovial  bursa, 
and  the  lateral  inferior  genicular  artery.  On  this  account, 
although  both  menisci  are  permitted  a  certain  amount  of  move- 
ment to  enable  them  to  accommodate  themselves  to  the  articular 
surfaces  in  different  positions  of  the  joint,  the  medial  meniscus 
is  the  less  freely  movable  of  the  two.  Further,  since  the 


FIG.  133. — The  Menisci  and  their  Attachments. 


1.  Transverse  ligament. 

2.  Anterior  cornu  of  medial  meniscus. 

3.  Anterior  cruciate  ligament. 

4.  Medial  tubercle  of  intercondyloid  emin- 

ence of  tibia. 

5.  Medial  meniscus. 

6.  Posterior  cornu  of  medial  meniscus. 

7.  Posterior  cruciate  ligament. 


8.  Fasciculus  from    lateral   meniscus  to 

posterior  cruciate  ligament. 

9.  Posterior  cornu  of  lateral  meniscus. 

10.  Lateral     tubercle     of     intercondyloid 

eminence  of  tibia. 

11.  Lateral  meniscus. 

12.  Anterior  cornu  of  lateral  meniscus. 


extremities  of  the  medial  meniscus  are  more  widely  separated 
from  one  another  than  those  of  the  lateral  meniscus,  the  latter 
enjoys  greater  freedom. 

Injuries  of  the  menisci  occur  in  forcible  rotation  of  the  flexed 
or  semi-flexed  knee.  The  tibia  may  be  rotated  on  the  femur 
when  the  latter  is  fixed,  or  the  femur  may  be  rotated  on  the 
tibia  when  the  tibia  is  fixed.  Statistics  show  that  the  medial 
meniscus  suffers  injury  much  more  frequently  than  does  the 
lateral  meniscus,  and  it  is  probable  that  the  comparative 
immunity  of  the  lateral  meniscus  is  due  to  its  greater  range  of 
movement. 

When  the  tibia  is  fixed  and  the  femur  is  suddenly  and 


THE  REGION  OF  THE  KNEE 


457 


violently  rotated  laterally,  the  lateral  meniscus  is  able  to  follow 
the  movements  of  the  lateral  condyle,  and  in  doing  so  it  exerts 
a  strain  on  the  thin  concave  margin  of  the  medial  meniscus 
through  the  transverse  ligament.  As  a  result  a  concentric 
splitting  may  occur  in  the  anterior  part  of  the  medial  meniscus, 
or  its  anterior  extremity  may  be  torn  through  and  dragged 
towards  the  centre  of  the  joint  (Fig.  134,  B). 

In  some  subjects,  either  owing  to  their  occupation  or  as  the 


FIG.  134. — Diagram  to  illustrate  Injuries  of  the  Medial  Meniscus. 

A.  Normal  position  of  the  menisci. 

B.  Splitting  of  the  medial  meniscus  caused  by  traction  on  the  transverse  ligament, 
following  violent  lateral  rotation  of  the  femur  on  the  fixed  tibia. 

C  and  D.  Tearing  of  the  anterior  attachment  of  the  medial  meniscus  caused  by  violent 
flexion  of  the  knee  combined  with  medial  rotation  of  the  femur  on  the  fixed  tibia. 

result  of  a  constitutional  disease,  the  capsule  of  the  knee-joint 
becomes  sufficiently  relaxed  to  permit  a  slight  amount  of 
abduction  and  adduction.  This  constitutes  a  predisposing 
cause  to  injury,  as,  owing  to  the  increased  freedom  of  separation 
of  the  femur  and  tibia  from  each  other,  the  menisci  are  more 
likely  to  be  caught  between  the  two  articular  surfaces.  In 
extension  of  the  knee-joint  the  somewhat  flattened  distal  surface 
of  the  medial  condyle  of  the  femur  is  in  contact  with  the  whole 
of  the  medial  meniscus.  When  the  leg  is  extended,  therefore, 
forcible  medial  rotation  of  the  femur  on  the  tibia  produces  little 
alteration  in  the  shape  of  the  meniscus.  On  the  other  hand, 


458  THE  INFERIOR  EXTREMITY 

when  the  leg  is  flexed  the  more  convex  posterior  surface  of  the 
femoral  condyle  is  only  in  contact  with  the  broader  posterior 
part  of  the  medial  meniscus,  and  in  medial  rotation  of  the 
femur  on  the  tibia  the  curve  of  this  part  is  accentuated,  while 
the  anterior  part  becomes  correspondingly  straighter.  If  the 
violence  of  the  rotatory  movement  is  sufficient  to  tear  its  anterior 
attachment,  the  meniscus  resumes  its  semilunar  outline,  with 
the  result  that  its  torn  extremity  projects  into  the  centre  of  the 
joint  (Fig.  134).  Subsequent  extension  of  the  joint  catches  the 
meniscus  between  the  two  articular  surfaces. 

The  Surgical  Approach  to  the  menisci  is  carried  out  with 
the  knee-joint  flexed  (Jones)  in  order  to  obtain  good  exposure. 
The  incision,  which  is  convex  forwards  and  extends  for  two  inches 
on  each  side  of  the  line  of  the  joint,  does  not  quite  reach  the 
margin  of  the  patella,  and  a  curved  flap  of  skin  and  fascia  is 
reflected  backwards.  A  vertical  incision  is  made  in  the  capsule 
midway  between  the  patella  and  the  margin  of  the  femoral 
condyle,  and  the  anterior  extremity  of  the  meniscus  can  then  be 
dragged  forwards  out  of  the  wound.  After  it  has  been  dealt  with 
the  capsule  is  closed  and  the  skin  margins  are  reunited.  As 
the  incision  through  the  skin  does  not  immediately  overlie  the 
incision  through  the  capsule,  leakage  of  the  synovial  fluid  is 
hindered,  while  there  is  no  subsequent  weakening  of  the  capsule 
in  flexion  and  extension,  such  as  occurs  when  the  incision 
through  it  is  made  in  a  transverse  direction. 

The  Cruciate  Ligaments  extend  from  the  intercondylar 
fossa  of  the  femur  to  the  intercondylar  area  on  the  top  of  the 
tibia.  They  cross  one  another  in  the  centre  of  the  joint  and  are 
therefore  iritra-capsular,  but  they  are  excluded  from  the  synovial 
cavity  by  the  synovial  membrane.  The  anterior  cruciate  ligament 
is  attached  to  the  top  of  the  tibia  in  front  of  the  intercondylar 
eminence,  and  passes  upwards  and  backwards  to  reach  the 
posterior  part  of  the  medial  aspect  of  the  lateral  femoral  condyle. 
These  two  bony  points  are  farthest  from  one  another  when  the 
knee-joint  is  fully  extended,  and  in  this  position  of  the  limb, 
therefore,  the  ligament  is  tense.  Aided  by  the  collateral 
ligaments  and  the  thickened  posterior  part  of  the  capsule,  the 
anterior  cruciate  ligament  is  sufficiently  strong  to  prevent 
hyper-extension  of  the  joint  unless  excessive  force  is  applied. 
The  posterior  cruciate  ligament  is  attached  to  the  posterior  part 
of  the  non-articular  area  on  the  top  of  the  tibia,  and  extends 
upwards  and  forwards  to  the  anterior  part  of  the  lateral  aspect 


THE  REGION  OF  THE  KNEE  459 

of  the  medial  femoral  condyle.     It  is  relaxed  in  extension,  but 
becomes  tightened  during  flexion  of  the  joint. 

Severe  strains  of  the  knee  may  cause  rupture  of  one  or  both 
cruciate  ligaments  without  leading  to  actual  dislocation  of  the 
joint.  In  addition  to  preventing  hyperextension  of  the  knee, 
the  anterior  cruciate  ligament  prevents  the  tibia  from  being 
moved  bodily  forwards  on  the  femur  when  the  joint  is  passively 
extended.  If,  following  injury,  this  passive  movement  is 
obtained,  the  diagnosis  of  rupture  of  the  anterior  cruciate 
ligament  can  be  made  with  some  degree  of  certainty.  Similarly 
the  posterior  cruciate  ligament  prevents  the  same  passive 
movement  of  the  tibia  on  the  femur  when  the  knee  is  flexed, 
and  this  movement  can  only  be  obtained  when  the  ligament 
is  ruptured. 

The  articular  surfaces  of  the  tibial  condyles  are  separated  from  one 
another  by  a  roughened  non-articular  area,  which  corresponds  to  the  inter- 
condylar  fossa  of  the  femur.  This  area,  which  is  narrowest  centrally,  where 
it  is  raised  up  to  form  the  inter condylar  eminence  (tibial  spine),  gives  attach- 
ment to  the  inter-articular  menisci  and  ligaments.  Near  its  anterior  margin 
it  gives  attachment  to  the  anterior  extremity  of  the  medial  meniscus  and 
to  the  anterior  cruciate  ligament.  The  anterior  extremity  of  the  lateral 
meniscus  is  attached  immediately  in  front  of  the  intercondylar  eminence, 
while  its  posterior  extremity  is  attached  to  the  eminence  itself.  The  posterior 
extremity  of  the  medial  meniscus  receives  attachment  immediately  behind 
the  eminence,  and  behind  that  lie  the  posterior  cruciate  ligament  and  the 
posterior  part  of  the  capsule  (Fig.  133). 

Fracture  of  the  Intercondylar  Eminence  (Spine)  of  the  Tibia  is  a 
somewhat  rare  injury,  which  has  been  brought  to  light  by  the  use  of  radio- 
graphy. Forcible  extension  of  the  femur  upon  the  fixed  and  medially 
rotated  tibia  causes  the  lateral  margin  of  the  medial  femoral  condyle  to 
impinge  on  the  medial  tubercle  of  the  eminence,  and  so  fracture  it.  Similarly, 
when  the  tibia  is  fixed  in  lateral  rotation,  forcible  extension  may  cause  the 
lateral  condyle  to  fracture  the  lateral  tubercle  of  the  eminence  (Jones). 

It  would  appear  that  the  injury  only  occurs  in  cases  where  one  or  other 
tubercle  is  unusually  well  developed.  The  condition  causes  limitation  of 
movement,  especially  of  extension,  and  if  absolute  rest  in  the  extended 
position  fails  to  produce  a  good  result,  or  if  the  case  is  one  of  long  standing, 
operative  interference  is  advisable.  The  best  exposure  is  obtained  by  splitting 
the  patella  vertically,  the  knee  being  kept  flexed.  When  the  two  fragments 
are  separated,  the  patellar  sy  no  vial  fold  (ligamentum  mucosum,  p.  452)  is 
exposed  and  divided,  and  the  region  of  the  intercondylar  eminence  can  then 
be  investigated.  There  is  no  necessity  to  wire  the  patella  subsequently. 

Spread  of  Tuberculous  Disease  in  the  Region  of 
the  Knee-Joint. — Tuberculous  disease  at  the  distal  end  of  the 
femur  usually  commences  in  the  distal  part  of  the  diaphysis, 
and  nearer  to  its  posterior  than  to  its  anterior  surface.  It  may 
spread  upwards  along  the  diaphysis,  or  it  may  pass  horizontally 
towards  the  surface.  In  the  latter  case  it  usually  spreads 


460  THE  INFERIOR  EXTREMITY 

backwards  and  readily  breaks  through  the  thin  compact  bone 
(cortex)  of  the  popliteal  surface  of  the  femur,  giving  rise  to  a 
popliteal  abscess.  Tuberculous  disease  originating  in  the  distal 
part  of  the  femoral  diaphysis  rarely  involves  the  knee-joint, 
since  in  the  first  place,  it  is  extra-capsular ;  and  in  the  second 
place,  it  finds  less  difficulty  in  spreading  to  the  popliteal  fossa 
than  in  passing  through  the  epiphysis  to  gain  the  joint.  If, 
however,  the  disease  spreads  forwards  and  breaks  through  the 
periosteum,  it  infects  the  supra-patellar  bursa  and  then  involves 
the  joint. 

When  tuberculous  disease  originates  in  the  proximal  end  of 
the  tibial  diaphysis  it  is  entirely  extra-capsular,  and  it  commonly 
spreads  distally  along  the  shaft.  It  may,  however,  penetrate 
the  periosteum  and  infect  the  soft  parts  on  the  posterior  or 
lateral  aspects,  or  cause  a  subcutaneous  abscess  on  the  medial 
aspect.  Very  rarely  the  disease  may  break  through  the  articular 
cartilage  and  infect  the  proximal  tibio-fibular  joint.  Should 
this  joint  cavity  communicate  with  the  knee-joint  through  the 
popliteus  bursa  (p.  449),  the  knee-joint  itself  will  be  secondarily 
infected. 

When  the  patella  is  the  primary  site  of  tuberculous  disease, 
spread  to  the  knee-joint  is  likely  to  occur,  since  only  the  articular 
cartilage  intervenes. 

The  Surgical  Approach  to  the  Knee- Joint.  —  The 
route  chosen  in  any  particular  case  depends  partly  on  the  area 
of  the  joint  which  is  involved  and  partly  on  the  ultimate  aim 
of  the  operation.  The  age  of  the  patient,  too,  may  have  some 
influence  in  determining  the  procedure  to  be  adopted. 

Drainage  is  difficult  to  obtain  in  suppurative  arthritis  owing 
to  the  complicated  arrangement  of  the  synovial  membrane. 
Incisions  may  be  made  midway  between  the  margin  of  the 
femoral  condyle  and  the  margin  of  the  patella,  on  each  side,  in 
order  to  allow  a  tube  to  be  passed  across  the  joint.  From  the 
medial  opening  a  director  may  be  passed  backwards  across  the 
medial  surface  of  the  medial  condyle  of  the  femur  just  below 
the  attachment  of  the  tibial  collateral  ligament.  The  point  of 
the  instrument  is  cut  down  upon  when  it  reaches  the  posterior 
synovial  pouch  (p.  462).  A  similar  proceeding  can  be  carried 
out  on  the  lateral  side,  and,  finally,  an  incision  should  be  made 
into  the  proximal  part  of  the  supra-patellar  bursa.  Through 
these  various  incisions  tubes  may  be  arranged  so  as  to  provide 
adequate  drainage. 


THE  REGION  OF  THE  KNEE 


461 


In  young  subjects,  Inspection  of  the  Joint  may  be  carried  out 
with  least  damage  through  the  lateral  J -shaped  incision  of 
Kocher  or  through  a  similar  incision  on  the  medial  side.  The 


Cut  edge  of  synovial  membrane 


Posterior  surface 
of  patella 


Posterior  cruciate 
ligament 
Patellar  synovial 
fold  (ligamentum 
mucosum) 
Anterior  cruciate 
ligament 

Anterior  cornu  of 
lateral  meniscus 


Infra-patellar  pad  of  fat 


Ligamentum  patellae,  „ 
posterior  surface 


Tuberosity  of  tibia, 
posterior  cut  surface 


Periosteum  of  tibia,  left  attached 
to  tuberosity 


FIG.  135.  — Complete  Exposure  of  the  Knee-joint.    The  dissection  is  described 
on  p.  462.     The  synovial  membrane  is  shown  in  purple. 

limb  is  slightly  flexed  over  a  sandbag,  as  the  interior  of  the  joint 
is  most  accessible  in  this  position.  The  incision,  which  begins 
about  2\  inches  proximal  to  the  patella  and  a  ringer's  breadth 
from  its  lateral  margin,  descends  vertically  over  the  femoral 
and  tibial  condyles  and  then  curves  gently  forwards  to  a  point 


462  THE  INFERIOR  EXTREMITY 

about  i£  inches  beyond  the  tibial  tuberosity.  When  the  skin 
and  fasciae  have  been  elevated  and  retracted;  the  vastus  lateralis 
and  its  tendinous  expansion  which  passes  to  the  lateral  border 
of  the  patella  are  exposed,  together  with  the  patella  and  the 
ligamentum  patellae.  The  joint  is  then  opened  by  deepening 
the  vertical  part  of  the  incision.  Freer  access  is  gained  by 
dividing  the  infra-patellar  pad  of  fat  and  its  synovial  covering 
and  by  elevating  the  ligamentum  patellae  from  the  tibia.  In 
the  child  the  ligament  is  freed  by  removing  a  slice  of  cartilage 
from  the  tibial  tuberosity,  but  in  the  adult  the  tuberosity  will 
require  to  be  chipped  off  with  a  chisel.  In  both  cases  the 
periosteum  at  the  distal  border  of  the  tuberosity  must  not  be 
divided,  since  it  serves  to  retain  the  tuberosity  in  position 
subsequently.  Thereafter  the  patella,  together  with  the 
quadriceps  and  the  ligamentum  patellae,  may  be  rotated  through 
a  right  angle,  and  its  surfaces  can  then  be  reversed  by  flexing 
the  knee.  The  whole  of  the  joint  cavity  is  then  exposed,  and 
if  necessary,  excision  of  the  joint  can  be  performed  (Fig.  135). 

Excision  of  the  Knee- Joint. — When  it  is  decided  before 
the  operation  that  excision  of  the  joint  is  necessary,  a  large 
U-shaped  incision  gives  the  best  access.  The  transverse  limb 
lies  midway  between  the  patella  and  the  tibial  tuberosity,  and 
the  vertical  limbs  ascend  immediately  in  front  of  the  collateral 
ligaments.  This  incision  is  to  be  recommended  because  it 
provides  an  anterior  flap,  should  the  condition  of  the  joint,  as 
revealed  by  the  operation,  call  for  amputation  rather  than 
excision. 

The  initial  incision  divides  the  skin,  fascia,  and  the 
supra-patellar  tendon,  and  opens  into  the  cavity  of  the  joint, 
which  may  be  widely  exposed  by  flexing  the  knee. 

The  cruciate  ligaments  are  then  removed,  and  this  step 
enables  the  surgeon  to  dissect  the  synovial  membrane  from  the 
lateral  and  medial  parts  of  the  posterior  ligament.  In  this 
situation  synovial  pouches  extend  upwards  behind  the  condyles, 
and,  unless  they  are  removed,  they  may  give  rise  to  subsequent 
recurrence  of  the  disease. 

After  resection  of  the  cruciate  ligaments,  it  is  impossible  to 
obtain  a  joint  which  is  both  stable  and  movable,  and  as  stability 
is  of  primary  importance,  osseous  ankylosis  should  be  aimed  at. 
This  result  is  obtained  by  removing  the  articular  cartilage  and 
a  layer  of  bone  from  the  condyles  of  the  femur  and  tibia.  When 
the  disease  has  originated  in  the  synovial  membrane  and  the 


THE  REGION  OF  THE  KNEE  463 

bones  are  not  affected,  the  amount  of  bone  removed  should  be 
just  sufficient  to  ensure  firm  osseous  union.  In  these  cases  the 
femur  is  divided  just  distal  to  the  attachments  of  the  collateral 
ligaments,  while  a  slice,  a  quarter  of  an  inch  thick,  is  removed 
from  the  tibia.  Owing  to  the  obliquity  of  its  long  axis  (p.  464), 
the  femur  must  be  divided  parallel  to  the  line  of  the  joint  and  not 
at  right  angles  to  its  axis,  in  order  to  maintain  the  limb  in  its 
normal  alignment.  Since  the  epiphyseal  lines  are  not  interfered 
with  in  either  bone,  the  amount  of  permanent  shortening  is 
usually  slight,  and  it  serves  to  prevent  the  foot  from  dragging 
on  the  ground  when  the  patient  is  able  to  walk  again. 

The  articular  surface  of  the  patella  and  the  anterior  articular 
surface  of  the  condyles  should  also  be  removed  in  order  to 
render  the  resulting  ankylosis  more  secure. 

The  posterior  ligament  of  the  joint  is  left  intact  when 
possible,  as  it  protects  the  vessels  in  the  popliteal  fossa  (Fig. 
131).  The  middle  genicular  (azygos)  artery  will  require  to  be 
ligatured  as  it  enters  the  joint  after  piercing  the  ligament. 

After  the  anterior  flap  of  skin  and  fascia  has  been  replaced, 
but  before  it  is  sutured,  a  long  nail  may  be  driven  through  each 
tibial  condyle  into  the  corresponding  condyle  of  the  femur. 
These  nails  should  be  introduced  parallel  to  the  long  axis  of  the 
tibia,  and  care  must  be  taken  lest  they  penetrate  the  popliteal 
surface  of  the  femur.  This  arrangement  secures  the  bones  in 
position  until  bony  union  occurs.  Thereafter  the  wound  is 
stitched  up  in  layers. 

Genu  Valgum. — Under  normal  conditions  a  line  drawn 
from  the  centre  of  the  femoral  head  to  a  point  midway  between 
the  two  malleoli  passes  midway  between  the  femoral  condyles 
at  the  knee-joint.  In  this  way  the  weight  of  the  trunk  is 
transmitted  evenly  to  the  two  tibial  condyles  and  thence  to 
the  tarsal  bones. 

In  rickets,  owing  to  irregular  growth  and  ossification  near 
the  epiphyseal  line,  the  medial  part  of  the  distal  extremity  of 
the  femoral  diaphysis  may  become  abnormally  enlarged  in  a 
downward  direction.  As  a  result,  the  medial  part  of  the 
epiphysis  is  thrust  distally  so  that  the  plane  of  the  knee-joint 
is  directed  downwards,  backwards  and  laterally  instead  of 
vertically  downwards.  This  constitutes  the  condition  of  genu 
valgum.  A  plumb-line  dropped  from  the  femoral  head  passes 
to  the  lateral  side  of  the  centre  of  the  knee-joint  and  to  the 
medial  side  of  the  centre  of  the  ankle-joint.  The  deformity 


464  THE  INFERIOR  EXTREMITY 

may  be  so  great  that  the  angle  between  the  long  axes  of  the 
femur  and  tibia,  which  is  normally  about  170°,  may  approach 
90°.  When  the  knee  is  flexed,  however,  the  deformity  disappears, 


FIG.  136. — Genu  Valgum.  (From  a  Radiogram  by  Dr.  Claude  Gouldes- 
brough. )  Observe  the  increased  growth  of  the  medial  part  of  the  distal 
end  of  the  diaphysis  of  the  femur. 

as  the  posterior  surfaces  of  the  femoral  condyles  are  not  affected 
and  the  tibia  itself  has  undergone  no  alteration.  The  weight 
of  the  trunk  is  no  longer  transmitted  evenly  to  the  tarsus,  the 
pressure  being  now  distributed  over  the  medial  border  of  the 
foot.  An  undue  strain  is  therefore  thrown  on  the  plantar 


THE  REGION  OF  THE  KNEE  465 

calcaneo-navicular  ("  spring ")  ligament  (p.  484),  and  the 
condition  of  flat-foot  is  brought  about.  In  some  cases  flat-foot 
is  not  the  result  but  the  cause  of  genu  valgum.  In  the  attitude 
of  rest  adopted  by  young  adolescents  who  are  the  subjects  of 
flat-foot,  the  feet  are  turned  laterally  and  separated  widely 
from  one  another,  while  the  knees  are  slightly  flexed  and  the 
thighs  are  adducted.  When  the  limbs  are  in  this  position,  the 
medial  condyle  of  the  femur  is  tilted  up  off  the  tibia,  stretch- 
ing the  tibial  collateral  ligament.  The  body-weight  is  now 
transmitted  through  the  lateral  condyle  of  the  femur,  and 
owing  to  the  diminished  pressure  on  the  medial  part  of  the 
epiphyseal  cartilage,  the  medial  part  of  the  distal  extremity  of 
the  diaphysis  undergoes  abnormal  growth.  Thus  the  apparent 
genu  valgum  of  the  attitude  of  rest  becomes  transformed  into 
a  real  genu  valgum. 

Certain  anatomical  changes  are  found  in  adults  in  whom 
the  rhachitic  knock-knee  of  childhood  has  been  permitted  to 
remain  uncorrected.  The  patella  may  become  displaced 
laterally  so  that,  on  flexion  of  the  knees,  it  slips  backwards  over 
the  lateral  aspect  of  the  joint.  The  biceps  tendon  sometimes 
becomes  shortened  and  causes  an  appreciable  amount  of  lateral 
rotation  of  the  tibia.  The  disability  caused  by  these  changes 
may  be  relieved  by  medial  cuneiform  osteotomy  of  the  femur 
(p.  438),  combined  with  transplantation  of  the  tibial  tuberosity 
with  the  attached  ligamentum  patellae  to  the  medial  aspect  of 
the  tibia,  in  exaggerated  cases. 

Genu  Varum.— Overgrowth  of  the  lateral  part  of  the 
distal  extremity  of  the  femoral  diaphysis  or  of  the  opposing 
part  of  the  tibial  diaphysis  may  occur  in  rickets,  giving  rise  to 
the  condition  of  "  bow-knee  "  or  genu  varum.  In  this  case 
the  plumb-line  dropped  from  the  centre  of  the  femoral  head 
passes  medial  to  the  centre  of  the  knee-joint,  but  lateral  to  the 
centre  of  the  ankle-joint.  As  a  result,  the  body- weight  is 
distributed  mainly  over  the  lateral  part  of  the  foot,  which  is 
so  well  adapted  to  bear  the  increased  strain  (p.  492)  that  but 
little  disability  is  experienced.  Further,  since  the  knees  are 
widely  separated,  they  do  not  have  to  avoid  each  other  in 
walking,  as  is  the  case  in  genu  valgum. 

If  the  child  is  kept  off  its  feet,  the  bones  tend  to  recover 
their  normal  shape.  This  tendency  is  only  apparent  so  long 
as  the  bones  remain  soft.  After  the  age  of  six  or  seven  the 
rhachitic  softening  disappears  and  the  bones  become  more 

30 


466  THE  INFERIOR  EXTREMITY 

brittle.  After  this  age,  therefore,  subcutaneous  fracture  or 
cuneiform  osteotomy  (p.  438)  is  necessary  to  overcome  the 
deformity. 

Injuries  in  the  Region  of  the  Knee.— Supra-condylar 
Fracture  of  the  Femur  (p.  440)  is  sometimes  converted  into  a 
T-shaped  fracture  involving  the  knee-joint,  by  a  vertical  splitting 
of  the  distal  fragment  through  the  intercondylar  fossa.  The 
nature  of  the  injury  may  be  determined  by  the  widening  of  the 
distal  extremity  of  the  femur  and  the  independent  movements 
of  each  condyle,  and  of  the  femoral  shaft.  There  is  usually 
considerable  effusion  into  the  joint,  and  this,  together  with  the 
swelling  of  the  surrounding  parts,  may  mask  the  condition  to 
some  extent.  Manipulations  to  restore  the  correct  alignment 
are  carried  out  with  the  knee  flexed  in  order  to  relax  the 
gastrocnemius,  and  for  the  same  reason  the  limb  is  then  placed 
on  a  double-inclined  plane. 

Separation  of  the  Distal  Epiphysis  of  the  Femur  usually 
occurs  between  the  ages  of  ten  and  fourteen,  and  is  due  to  violent 
hyperextension  of  the  knee.  This  movement  throws  a  severe 
strain  on  the  posterior  part  of  the  capsule,  which  is  of  great 
strength  and  consequently  does  not  give  way.  The  strain  is 
therefore  transmitted  to  the  femoral  epiphysis  and  a  diastasis 
occurs.  The  causative  force  is  usually  applied  to  the  leg  from 
behind,  and  on  this  account  the  epiphysis  is  usually  displaced 
forwards,  overriding  the  distal  extremity  of  the  diaphysis. 

Though  this  injury  is  by  no  means  common,  it  is  of  great 
importance,  because  it  is  usually  complicated  by  injury  of  the 
popliteal  vessels.  The  laceration  is  frequently  so  extensive 
that  amputation  may  ultimately  be  necessary  owing  to  the 
occurrence  of  gangrene. 

Reduction  is  obtained  by  traction  on  the  leg  and  downward 
pressure  on  the  displaced  epiphysis,  the  knee  being  flexed,  and 
the  limb  is  then  slowly  extended.  If,  despite  these  manipulations, 
the  deformity  recurs,  the  limb  must  be  put  up  with  the  leg 
flexed. 

Fracture  of  Either  Condyle  alone  may  be  caused  by 
violent  movements  of  abduction  or  adduction.  When  the  limb 
is  straightened  there  is  little  displacement,  but  a  double-inclined 
plane  should  be  used  in  order  to  keep  the  gastrocnemius  relaxed. 
Less  severe  strains  of  a  similar  nature  may  result  in  avulsion 
of  the  femoral  attachment  of  a  collateral  ligament. 

Fracture  of  the  Patella  may  be  due  either  to  direct  or  to 


THE  REGION  OF  THE  KNEE 


467 


indirect  violence.  In  the  former  case,  the  displacement  is  slight 
because,  although  the  bone  may  be  comminuted,  the  expansions 
of  the  vasti  (lateralis  and  medialis)  are  not  torn  and  they  serve 
to  prevent  excessive  separation  of  the  fragments. 

Fractures  from  indirect  violence  are  brought  about  when  the 
patient,  in  the  act  of  falling  backwards,  attempts  to  recover 
his  balance  by  powerful  contraction  of  the  quadriceps.  At  the 
time  of  the  accident  the  knee  is  semi-flexed  and  the  patella  is 
snapped  across  the  patellar  surface  of  the  femur.  Rupture  of 
the  quadriceps  tendon  or  of  the 
ligamentum  patellae  are  alterna- 
tive possibilities  to  this  fracture. 
The  two  fragments  are  widely 
separated,  for,  after  the  bone  has 
given  way,  the  strain  tears  through 
the  expansions  of  the  vasti  ten- 
dons (lateral  patellar  ligaments). 

When  conservative  treatment 
is  adopted,  the  limb  is  placed  on 
an  inclined  plane,  with  the  knee 
extended  in  order  to  relax  the 
quadriceps.  The  flexion  of  the 
hip  still  further  relaxes  the  rectus 
femoris.  Fibrous  union,  together 
with  varying  degrees  of  separa- 
tion of  the  fragments,  may  be  the 
outcome  of  this  method  of  treat- 
ment, but  this  condition  does  not 
necessarily  cause  much  disability. 

If  the  fragments  are  to  be  wired, 
good  exposure  is  obtained  by  a  large  U-shaped  flap  (p.  462).  A 
strong  silver  wire  is  passed  transversely  through  each  fragment 
and  the  ends  are  twisted  together  at  the  margin  of  the  patella. 
In  this  way  the  wire  does  not  invade  either  the  articular  or  the 
subcutaneous  surface  of  the  bone  (Fig.  137). 

Dislocation  of  the  Patella  may  be  due  to  violence  or  to 
exaggerated  muscular  action,  occurring  when  the  limb  is  extended 
and  the  tendinous  expansions  of  the  vasti  are  relaxed.  The 
dislocation  is  usually  over  one  or  other  condyle,  but  occasionally 
the  bone  is  twisted  round  through  a  right  angle  so  that  its 
surfaces  look  medially  and  laterally.  Reduction  can  only  be 
effected  after  complete  relaxation  of  the  quadriceps. 


FIG.  137. — Diagram  to  illustrate 
how  a  Fractured  Patella  may  be 
wired,  without  interfering  with  the 
articular  surface. 

A.  Anterior  view. 

B.  Lateral  view. 


468  THE  INFERIOR  EXTREMITY 

Avulsion  of  the  Tibial  Tuberosity  occurs  in  youth  before 
the  completion  of  ossification  (p.  452),  and  is  usually  due  to 
excessive  muscular  strain.  Minor  degrees  of  this  accident  cause 
loosening  and  partial  separation  of  the  tuberosity.  If  untreated, 
the  condition  may  become  chronic  owing  to  repeated  strains 
and  want  of  rest,  and  it  then  gives  rise  to  lameness  and  to  pain 
and  swelling  locally  (Schlatter's  disease). 

Dislocation  of  the  Knee-Joint  is  a  somewhat  rare  injury.  In  the  least 
uncommon  variety  the  tibia  is  displaced  forwards  and  proximally  in  front 
of  the  femoral  condyles.  The  condition  results  from  violent  hyperextension 
and  the  cruciate  ligaments  are  torn,  while  the  posterior  ligament  is  either 
ruptured  or  stripped  up  with  the  periosteum  on  the  posterior  aspect  of  the 
tibia. 

Reduction  of  this  variety  is  obtained  by  downward  traction  on  the  leg 
and  direct  backward  pressure  on  the  proximal  extremity  of  the  tibia.  If 
this  method  is  unsuccessful,  hyperextension  may  be  added  to  the  previous 
manipulations,  but  it  may  result  in  injuries  to  the  large  nerves  in  the  popliteal 


In  posterior  dislocations,  which  result  from  direct  violence  applied  either 
to  the  front  of  the  leg  or  to  the  back  of  the  thigh,  the  proximal  extremity 
of  the  tibia  occupies  the  popliteal  fossa,  and  may  injure  or  compress  the 
popliteal  vessels. 

Ossification  of  the  Head  of  the  Fibula  begins  about  the 
third  year  and  forms  an  epiphysis,  which  unites  with  the  shaft 
between  the  ages  of  twenty  and  twenty-four.  Separation  of 
the  proximal  epiphysis  and  fractures  of  the  head  or  neck  of  the 
fibula  are  very  rare  injuries,  but  when  they  do  occur  they  are 
apt  to  involve  the  common  peroneal  (ext.  popliteal)  nerve 
(p.  446). 

When  tuberculous  disease  originates  in  the  fibular  diaphysis 
near  the  epiphyseal  cartilage,  it  does  not  commonly  spread  to 
the  proximal  tibio-fibular  joint,  as  the  epiphyseal  cartilage  is 
entirely  extra-capsular  (Fig.  132).  On  the  other  hand,  if  the 
disease  begins  in  the  proximo-lateral  part  of  the  tibial  diaphysis, 
the  joint  may  be  infected,  as  its  capsule  receives  partial  attach- 
ment to  the  tibial  diaphysis. 


THE    LEG. 

Surface  Landmarks. — The  medial  surface  of  the  tibia  is 
for  the  most  part  covered  only  by  the  skin  and  superficial 
fascia,  and  it  can  therefore  be  examined  without  difficulty. 
On  the  other  hand,  the  shaft  of  the  fibula  is  clothed  with  muscles 


THE  LEG  469 

on  all  sides,  and  its  palpation  is  by  no  means  easy.  The  outline 
of  the  bone  can  best  be  made  out  along  the  posterior  intermuscular 
septum  of  the  leg,  which  corresponds  to  a  line  drawn  from  the 
posterior  part  of  the  head  of  the  fibula  to  the  posterior  border 
of  the  lateral  malleolus. 

When  the  ankle  is  actively  dorsi-flexed,  the  muscular  belly 
of  the  tibialis  anterior  forms  a  prominent  elevation  on  the 
anterior  aspect  of  the  leg,  and  its  tendon  can  be  traced  distally 
and  medially  across  the  front  of  the  ankle-joint  (p.  479).  The 
flexors  of  the  ankle  and  extensors  of  the  toes  are  separated 
from  the  peroneal  muscles,  which  act  as  evertors  of  the  foot, 
by  the  anterior  intermuscular  septum  of  the  leg.  This  septum 
corresponds  to  a  line  drawn  from  the  anterior  aspect  of  the 
fibular  head  to  the  anterior  margin  of  the  lateral  malleolus.  In 
eversion  of  the  foot  the  peroneal  muscles  form  a  surface  elevation 
on  the  lateral  aspect  of  the  leg  immediately  behind  the  line  of 
the  septum.  This  elevation  is  limited  posteriorly  by  a 
longitudinal  furrow,  which  marks  the  position  of  the  posterior 
intermuscular  septum  and  separates  the  peroneal  muscles  from 
the  muscles  of  the  calf. 

The  lateral  margin  of  the  soleus  is  rendered  prominent  when 
the  subject  stands  on  tip-toe.  It  forms  a  narrow  elevation 
behind  the  posterior  intermuscular  septum,  and  it  disappears 
proximally  under  cover  of  the  gastrocnemius. 

The  common  peroneal  nerve  can  be  rolled  against  the  bone,  as 
it  lies  first  behind  the  head  and  then  lateral  to  the  neck  of  the 
fibula.  Its  superficial  position  and  its  close  relationship  to  the 
bone  render  the  nerve  liable  to  injury  from  bruising  or  following 
fractures  of  the  fibular  neck.  It  is  occasionally  divided  in 
bullet  and  scythe  wounds. 

The  Deep  Fascia  of  the  Leg. — The  deep  fascia  is  entirely 
absent  over  the  medial  surface  of  the  tibia,  and  it  forms  a 
relatively  thin  sheet  over  the  posterior  aspect  of  the  leg.  It 
is  more  strongly  developed  over  the  lateral  and  anterior  aspects, 
and  is  specially  strong  over  the  proximal  part  of  the  tibialis 
anterior.  The  anterior  and  the  posterior  intermuscular  septa 
attach  its  deep  surface  to  the  corresponding  borders  of  the  fibula. 
In  the  region  of  the  ankle-joint  the  deep  fascia  is  strengthened 
to  form  ligamentous  bands  which  retain  the  various  tendons  in 
position. 

The  transverse  ligament  stretches  between  the  anterior  borders 
of  the  tibia  and  fibula  immediately  proximal  to  the  malleoli. 

30  a 


470  THE  INFERIOR  EXTREMITY 

The  cruciate  ligament  is  made  up  of  two  bands,  of  which  one 


Tibia,  anterior  border  —  j 
Tibialis  anterior- 


Extensor  digitoruni  longu 


Anterior  tibial  artery- 

Peronseus  longus- 
Peronaeus  brevis 


Peronaeus  tertius 

Cruciate  ligament 

Dorsalis  pedis  artery 
Tendon  of  tibialis  anterior-- 
Tendon of  Peronaeus  tertiu 
Extensor  digitorum  brevi 
Tendon  of  Extensor 
hallucis  longus 


--Extensor  hallucis  longus 
•Transverse  ligament 


FIG.  138. — Muscles  and  Tendons  on  the  Front  of  the  Leg  and  Dorsum 
of  Foot. 

extends  from  the  lateral  malleolus  to  the  medial  margin  of  the 
plantar  fascia  and  the  other  from  the  medial  malleolus  to  the 


THE  LEG  471 

upper  surface  of  the  calcaneus  (p.  478).  These  ligaments  are 
split  by  the  tendons  of  the  anterior  compartment  of  the  leg. 
The  transverse  ligament  possesses  two  compartments,  of  which 
the  medial  is  occupied  by  the  tibialis  anterior  and  the  lateial 
by  the  extensor  hallucis  longus,  the  extensor  digitorum  longus, 
and  the  peronseus  tertius.  A  similar  arrangement  exists  at  the 
cruciate  ligament,  with  the  exception  that  the  extensor  hallucis 
longus  possesses  a  separate  compartment,  intermediate  in 
position  between  the  other  two.  As  the  tendons  traverse  the 
ligaments,  they  are  surrounded  by  synovial  sheaths,  which 
extend  for  variable  distances  upon  them. 

On  the  medial  side  of  the  ankle-joint  the  deep  fascia  is 
thickened  to  form  the  laciniate  (internal  annular)  ligament) 
which  holds  in  place  the  tendons  of  the  tibialis  posterior,  the 
flexor  digitorum  longus,  and  the  flexor  hallucis  longus.  Synovial 
sheaths  enclose  these  tendons,  as  they  lie  under  the  ligament, 
and  extend  forwards  along  them  into  the  sole  of  the  foot. 

Two  similar  bands  are  placed  on  the  lateral  side  of  the  ankle 
in  relation  to  the  tendons  of  the  peronaeus  longus  and  brevis. 
The  superior  retinaculum  lies  behind  the  lateral  malleolus  and 
possesses  a  single  compartment,  lined  by  a  common  synovial 
sheath.  The  inferior  retinaculum  extends  from  the  tip  of  the 
lateral  malleolus  to  the  lateral  aspect  of  the  calcaneus  below 
the  trochlear  process.  It  possesses  two  compartments  separated 
by  the  process  and  lined  by  synovial  sheaths  which  are  continuous 
with  the  common  sheath  under  the  superior  retinaculum. 
Either  retinaculum  may  be  ruptured  by  violent  contraction 
of  the  peronaei,  and  the  tendons  are  subsequently  easily 
displaced. 

Anterior  Compartment  of  the  Leg. — The  Tibialis  Anterior  arises  from 
the  proximal  two-thirds  of  the  lateral  surface  of  the  tibia  and  the  adjoining 
part  of  the  interosseous  membrane.  Its  tendon  runs  distally  and  medially, 
passing  behind  the  transverse  and  cruciate  ligaments,  to  be  inserted  into  the 
medial  side  of  the  base  of  the  first  metatarsal  and  the  adjoining  part  of  the 
medial  cuneiform.  The  muscle  acts  as  a  flexor  of  the  ankle  and  an  inverter 
of  the  foot.  It  is  supplied  by  the  deep  peroneal  (ant.  tibial)  nerve  (L.  4,  5, 
and  S.  i). 

The  Extensor  Digitorum  Longus,  the  Extensor  Hallucis  Longus,  and  the 
Peronceus  Tertius  arise  from  the  fibula  and  occupy  the  lateral  part  of  the 
anterior  compartment.  The  former  two  are  inserted  into  the  distal  phalanges  ; 
they  flex  the  ankle-joint  and  extend  the  toes.  The  peronseus  tertius  is  in- 
serted into  the  dorsum  of  the  base  of  the  fifth  metatarsal ;  it  flexes  the  ankle- 
joint  and  everts  the  foot.  All  three  are  supplied  by  the  deep  peroneal  (anterior 
tibial)  nerve  (L.  4,  5,  and  S.  i). 

The  Anterior  Tibial  Artery  arises  from  the  popliteal  at  the 

30  & 


472  THE  INFERIOR  EXTREMITY 

distal  border  of  the  popliteus,  and  at  once  passes  forwards 
through  the  proximal  part  of  the  interosseous  membrane.  Its 
course  corresponds  to  a  line  drawn  from  a  point  i£  inches  lateral 
to  the  tuberosity  of  the  tibia  to  a  second  point,  situated  midway 
between  the  two  malleoli.  In  ligature  of  the  vessel,  the  incision 
is  made  along  this  line,  and,  after  the  deep  fascia  has  been 
divided,  the  tibialis  anterior  is  retracted  medially,  and  the  other 
muscles  laterally.  The  artery  is  then  exposed  lying  on  the 
interosseous  membrane  with  the  deep  peroneal  nerve  either  on 
its  lateral  (proximal  third)  or  anterior  aspect  (middle  third). 
In  the  distal  third  of  the  leg  the  artery  lies  on  the  tibia,  and  is 
crossed  obliquely  by  the  tendon  of  the  extensor  hallucis  longus. 
The  deep  peroneal  nerve  again  lies  to  its  lateral  side. 

After  ligature  of  the  anterior  tibial  artery,  the  circulation 
is  re-established  through  the  anastomosis  around  the  lateral 
malleolus  (p.  482)  and  the  connection  between  the  dorsalis  pedis 
artery  and  the  plantar  arch. 

The  Deep  Peroneal  (Anterior  Tibial)  Nerve  (L.  4,  5,  and 
S.  i)  arises  from  the  common  peroneal  (external  popliteal)  on 
the  lateral  aspect  of  the  fibular  neck  and  descends  through  the 
anterior  compartment  of  the  leg  in  close  relation  to  the  anterior 
tibial  artery.  It  supplies  all  the  muscles  in  the  anterior 
compartment  and  ends  in  front  of  the  ankle-joint,  by  dividing 
into  lateral  and  medial  branches. 

The  lateral  branch  supplies  the  extensor  digitorum  brevis 
and  the  neighbouring  articulations  ;  the  medial  branch  supplies 
the  dorsal  aspects  of  the  adjacent  borders  of  the  first  and  second 
toes. 

The  Dorsalis  Pedis  Artery  is  the  direct  continuation  of 
the  anterior  tibial.  It  commences  midway  between  the  two 
malleoli  and  runs  forwards  over  the  talus,  navicular,  and  second 
cuneiform  bones.  At  the  posterior  end  of  the  first  inter- 
metatarsal  space  it  passes  downwards  into  the  sole  of  the  foot 
and  joins  the  plantar  arterial  arch,  thus  establishing  an 
important  communication  between  the  anterior  and  posterior 
tibial  arteries.  It  is  placed  very  superficially,  and  its  pulsations 
can  readily  be  felt  on  the  lateral  side  of  the  flexor  hallucis  longus 
tendon. 

When  the  anterior  tibial  is  a  small  vessel,  the  dorsalis  pedis 
may  be  derived  from  the  perforating  branch  of  the  peroneal 
artery. 

The    Superficial     Peroneal    (Musculo-Cutaneous)    Nerve 


THE  LEG  473 

(L.  4,  5,  S.  i,  2)  arises  from  the  common  peroneal  nerve  opposite 
the  neck  of  the  fibula.  It  passes  forwards  between  the  bone 
and  the  peronaeus  longus  muscle,  and  then  descends  immediately 
behind  the  anterior  intermuscular  (peroneal)  septum.  In  this 
part  of  its  course  it  supplies  branches  to  the  peronseus  longus 
and  brevis  muscles.  At  the  junction  of  the  middle  and  distal 
thirds  of  the  anterior  intermuscular  septum  the  nerve  pierces 
the  deep  fascia  and  then  passes  distally  and  medially  across  the 
extensor  tendons.  It  supplies  the  skin  on  the  dorsum  of  the 
foot,  the  medial  side  of  the  dorsal  aspect  of  the  hallux,  and  the 


j Transverse  ligament 

Peronreus  longus 

iceus  brevis 
Superior  retinaculum 
Tendo  calcaneus 

nciate  ligament 
Extensor  digitorum  longus 

Extensor  digitorum  brevis 
sronseus  tertius 


Inferior  retinaculum      |      |  Peronreus  brevis 

Trochlear  process     Perona:us  longus 

FIG.  139. — The  Lateral  Aspect  of  the  Ankle  and  Foot. 

adjacent  sides  of  the  second,  third,  fourth,  and  fifth  toes.  The 
adjacent  sides  of  the  first  and  second  toes  are  supplied  by  the 
medial  division  of  the  deep  peroneal  (anterior  tibial)  nerve,  while 
the  lateral  side  of  the  fifth  toe  receives  branches  from  the  nervus 
suralis  (p.  446). 

The  Lateral  Compartment  of  the  Leg  is  occupied  by 
the  Peronseus  Longus  and  Brevis,  which  both  arise  from  the 
lateral  aspect  of  the  fibula  and  pass  down  behind  the  lateral 
malleolus.  In  this  situation  they  possess  a  common  synovial 
sheath  and  are  kept  in  place  by  the  superior  retinaculum  (p.  471). 
Below  the  lateral  malleolus  the  tendons  run  forwards  over  the 
lateral  aspect  of  the  calcaneus,  and  the  brevis  passes  above  and 
the  longus  below  the  trochlear  process.  In  this  situation  the 


474  THE  INFERIOR  EXTREMITY 

peronsei  are  retained  in  place  by  the  inferior  retinaculum  (p.  471), 
and  each  possesses  a  synovial  sheath,  which  is  continuous 
proximally  with  the  common  sheath. 

The  brevis  is  inserted  into  the  dorsal  aspect  of  the  tuberosity 
of  the  fifth  metatarsal,  and  its  synovial  sheath  reaches  almost 
to  the  insertion.  The  longus  enters  the  groove  on  the  plantar 
surface  of  the  cuboid  and  crosses  the  sole  of  the  foot  obliquely 
to  be  inserted  into  the  lateral  side  of  the  base  of  the  first 
metatarsal  and  the  adjoining  part  of  the  medial  cuneiform  (Fig. 
147).  In  the  foot  the  peronaeus  longus  is  very  deeply  placed, 
and  it  is  surrounded  by  a  synovial  sheath  which  may  or  may 
not  be  continuous  with  the  sheath  which  encloses  it  on  the 
lateral  aspect  of  the  ankle. 

Both  muscles  act  as  extensors  and  evertors  of  the  foot,  and 
they  are  supplied  by  the  superficial  peroneal  (musculo-cutaneous) 
nerve  (L.  4,  5,  and  S.  i). 

The  tendon  sheaths  of  the  peronsei  are  sometimes  the  site  of 
tuberculous  disease,  and  it  is  important  that  the  condition 
should  be  recognised  at  an  early  stage.  Otherwise  the  disease 
may  spread  along  the  sheath  of  the  longus  into  the  sole  of  the 
foot  and  infect  the  tarsal  joints.  Good  exposure  is  obtained 
by  a  lateral  J -shaped  incision  from  behind  the  lateral  malleolus 
to  the  base  of  the  fifth  metatarsal.  To  ensure  the  complete 
removal  of  the  disease,  the  retinacula  must  be  divided  and 
their  synovial  lining  dissected  away.  Thereafter  the  retinacula 
should  be  reunited  over  the  replaced  tendons. 

The  Posterior  Compartment  of  the  Leg.— The  muscles 
of  the  posterior  compartment  consist  of  a  superficial  and  a  deep 
group.  The  superficial  group  comprises  the  gastrocnemius, 
the  plantaris,  and  the  soleus,  while  the  deep  group  comprises 
the  flexor  hallucis  longus,  the  tibialis  posterior,  and  the  flexor 
digitorum  longus. 

The  Gastrocnemius  arises  from  the  distal  part  of  the  femur  by  two  heads 
of  origin,  which  are  inserted  into  a  common  tendon,  half-way  down  the  leg. 
The  Soleus,  which  lies  under  cover  of  the  preceding  muscle,  arises  from  the 
proximal  part  of  the  posterior  surface  of  the  fibula  and  by  a  linear  origin  from 
the  popliteal  line  and  the  medial  border  of  the  tibia.  These  two  muscles 
together  constitute  the  Triceps  Surse,  and  their  tendons  unite  to  form  the 
tendo  calcaneus  (Achillis),  which  is  inserted  into  the  middle  part  of  the  posterior 
surface  of  the  calcaneus.  A  small  bursa  is  interposed  between  the  tendon 
and  the  upper  part  of  the  posterior  surface  of  the  bone.  It  sometimes  becomes 
inflamed  after  excessive  walking,  and  it  may  be  affected  in  gout  or  gonorrhoeal 
rheumatism. 

The  Plantaris,  which  arises  close  to  the  lateral  head  of  the  gastrocnemius, 


THE  LEG  475 

has  a  short  muscular  belly  ending  in  a  long,  thin  tendon,  which  is  inserted  into 
the  calcaneus  on  the  medial  side  of  the  tendo  calcaneus. 

These  three  muscles  receive  their  nerve-supply  from  the  tibial  (internal 
popliteal)  nerve  (L.  4,  5,  S.  i  and  2),  and  they  act  as  extensors  of  the  ankle- 
joint.  In  addition,  the  gastrocnemius  and  plantaris  assist  in  flexing  the  knee- 
joint. 

Both  the  tendo  calcaneus  and  the  plantaris  tendon  may  be 
ruptured  by  violent  muscular  efforts  ;  in  the  case  of  the  former 
the  tendon  is  exposed  by  a  longitudinal  incision,  and  the  torn 
ends  are  sutured  together.  Occasionally,  instead  of  rupturing, 
the  tendo  calcaneus  tears  off  a  fragment  from  the  postero- 
superior  part  of  the  calcaneus — fracture  by  avulsion  (Fig.  146). 
In  this  case  the  incision  lies  along  the  lateral  border  of  the 
tendon  and  curves  forwards  along  the  lateral  surface  of  the 
calcaneus.  In  order  to  approximate  the  fragments  it  may  be 
necessary  to  lengthen  the  tendon,  and  this  may  be  effected  by 
a  series  of  hemi-divisions  along  each  border.  The  fragment  is 
then  screwed  into  place  and  the  foot  is  put  up  in  a  plaster  case, 
with  the  knee  flexed  and  the  toes  pointed  so  as  to  relax  the 
gastrocnemius  and  the  soleus  as  far  as  possible. 

The  Deep  Group  of  Muscles  is  separated  from  the  superficial  group  by 
a  strong  layer  of  the  deep  fascia,  which  extends  from  the  posterior  border 
of  the  fibula  to  the  medial  border  of  the  tibia. 

The  Tibialis  Posterior  arises  from  the  posterior  surface  of  the  interosseous 
membrane  and  the  adjoining  parts  of  the  tibia  and  fibula.  Its  tendon  passes 
distally  and  medially,  and,  as  it  grooves  the  medial  malleolus,  passes  through 
a  separate  compartment  of  the  laciniate  ligament.  It  is  mainly  inserted  into 
the  navicular  tuberosity  ;  but,  in  addition,  it  sends  strong  slips  to  all  the 
other  tarsal  bones  and  to  the  bases  of  the  middle  three  metatarsals.  These 
slips  strengthen  the  plantar  ligaments  of  the  foot  and  assist  in  maintaining 
the  longitudinal  and  transverse  arches  (p.  492). 

The  Flexor  Digitorum  Longus  arises  from  the  posterior  surface  of  the 
tibia,  medial  to  the  tibialis  posterior.  It  inclines  slightly  laterally  as  it 
descends,  and,  where  it  passes  through  the  laciniate  ligament,  it  lies  lateral 
to  the  tibialis  posterior  tendon. 

The  Flexor  Hallucis  Longus  arises  from  the  posterior  surface  of  the 
fibula,  lateral  to  the  tibialis  posterior.  Opposite  the  ankle-joint  it  passes 
through  a  separate  compartment  of  the  laciniate  ligament,  being  separated 
from  the  flexor  digitorum  longus  tendon  by  the  tibial  nerve  and  the  posterior 
tibial  vessels. 

All  three  muscles  are  supplied  by  the  tibial  nerve  (L.  5,  S.  i  and  2).  They 
act  as  extensors  of  the  ankle-joint,  but,  in  addition,  the  tibialis  posterior 
inverts  the  foot,  while  the  other  two  flex  the  toes. 

The  Posterior  Tibial  Artery  arises  from  the  popliteal  at 
the  distal  border  of  the  popliteus  and  descends  between  the 
deep  muscles  and  the  fascia  which  covers  them.  It  may  be 
mapped  out  on  the  surface  of  the  limb  by  a  line  drawn  from  the 
middle  of  the  popliteal  fossa  to  the  mid-point  between  the 


476  THE  INFERIOR  EXTREMITY 

tendo  calcaneus  and  the  medial  malleolus.  The  commencement 
of  the  artery  is  on  the  same  level  as  the  tibial  tuberosity.  At 
first  it  lies  on  the  tibialis  posterior,  but  near  the  ankle-joint  it 
is  placed  on  the  tibia  between  the  flexor  hallucis  longus  and  the 
flexor  digitorum  longus  tendons.  It  terminates  under  cover  of 
the  laciniate  ligament  by  dividing  into  the  lateral  and  medial 
plantar  arteries. 

Ligature  of  the  posterior  tibial  artery  is  usually  carried  out 
from  the  medial  side,  in  order  to  avoid  injuring  the  superficial 
group  of  muscles.  The  incision  is  made  a  finger's  breadth 
behind  the  medial  border  of  the  tibia  in  its  proximal  third,  and 
retraction  of  the  skin  and  fasciae  exposes  the  free  border  of  the 
medial  head  of  the  gastrocnemius,  which  overlaps  the  origin  of 
the  soleus  from  the  medial  border  of  the  tibia  (p.  474).  The 
wound  is  deepened  through  the  soleus,  exposing  the  strong 
fascia  which  covers  the  deep  muscles.  After  this  fascia  has  been 
carefully  split,  its  lateral  part  is  raised  from  the  underlying 
muscles,  and  the  posterior  tibial  artery  with  its  venae  comites 
is  exposed,  lying  on  the  tibialis  posterior.  In  the  proximal  third 
of  the  leg  the  tibial  nerve  lies  close  to  the  medial  side  of  the 
artery,  and  must  be  avoided  when  the  ligature  is  applied. 

The  Tibial  Nerve  passes  distally  through  the  posterior 
compartment  in  close  relation  to  the  posterior  tibial  vessels. 
At  first  it  lies  on  their  medial  side,  but  as  it  descends  it  crosses 
them  superficially  and  lies  on  their  lateral  side  at  the  ankle. 
It  gives  off  branches  of  supply  to  the  deep  muscles  (p.  475)  and 
terminates  under  the  laciniate  ligament  by  dividing  into  the 
lateral  and  medial  plantar  nerves. 

The  Peroneal  Artery  arises  from  the  posterior  tibial  soon  after  its  com- 
mencement and  runs  distally  in  association  with  the  flexor  hallucis  longus. 
It  lies  to  the  lateral  side  of  the  posterior  tibial  artery  and,  just  proximal  to 
the  ankle-joint,  gives  off  a  perforating  branch  which  pierces  the  interosseous 
membrane  and  descends  in  front  of  the  lateral  malleolus. 

The  Surgical  Approach  to  the  Tibia,  whether  for 
exploration  or  for  resection,  is  carried  out  along  the  medial 
surface  of  the  bone.  The  incision  is  vertical  and  is  carried  down 
to  the  periosteum,  care  being  taken  to  avoid  injuring  the 
saphenous  nerve  and  the  great  saphenous  vein  as  they  lie  in 
front  of  the  medial  malleolus.  Resection  of  the  whole  diaphysis, 
or  of  a  portion  of  it,  may  be  carried  out  in  the  manner  already 
described  in  the  case  of  the  humerus  (p.  39).  Along  the 
interosseous  crest  and  near  the  epiphyseal  cartilages  the 
periosteum  is  more  adherent  than  it  is  elsewhere,  and  it  is 


THE  REGION  OF  THE  ANKLE  AND  FOOT      477 

consequently  more  liable  to  injury  in  these  areas.  When  the 
epiphyseal  cartilage  is  affected  and  it  is  feared  that  shortening 
of  the  tibia  will  result,  subsequent  inversion  of  the  foot  may  be 
obviated  by  fracturing  the  fibula  and  allowing  the  ends  to 
overlap. 

In  the  Surgical  Approach  to  the  Fibula  the  incisions 
are  planned  to  avoid  injuring  the  superficial  peroneal  (musculo- 
cutaneous)  nerve.  Subperiosteal  resection  of  the  proximal  or 
middle  thirds  is  carried  out  through  an  incision  along  the  line 
of  the  posterior  intermuscular  septum.  In  the  proximal  third 
the  wound  is  deepened  between  the  adjoining  borders  of  the 
soleus  and  the  peronseus  longus,  and  care  must  be  taken  not 
to  injure  the  common  peroneal  nerve  as  it  winds  round  the 
fibular  neck. 

In  the  middle  third,  the  incision  exposes  the  peronseus  longus 
in  front  and  the  flexor  hallucis  longus  behind,  the  latter  muscle 
projecting  from  under  cover  of  the  lateral  border  of  the  soleus. 

In  the  distal  third,  the  incision  lies  just  posterior  to  the  anterior 
intermuscular  septum,  and  the  periosteum  is  divided  between 
the  peronseus  brevis  and  the  peronseus  tertius. 

Fractures  of  the  Leg  may  involve  one  or  both  bones. 
When  only  one  bone  is  fractured  there  is  little  displacement, 
and  the  sound  bone  acts  as  a  satisfactory  support. 

Both  bones  may  be  fractured  as  the  result  of  direct  or  indirect 
violence.  In  the  former  case  the  fractures  are  transverse  and 
occur  at  the  same  level  in  both  bones.  In  indirect  violence  the 
bones  give  way  at  different  levels,  the  tibia  at  the  junction  of  its 
middle  and  distal  thirds,  and  the  fibula  at  the  junction  of  its 
middle  and  proximal  thirds.  When  displacement  occurs,  it  is 
due  to  the  powerful  triceps  suras,  which  draws  the  distal 
fragments  upwards  behind  the  proximal  fragments  and  often 
causes  some  degree  of  anterior  angulation. 

As  the  medial  surface  of  the  tibia  is  covered  only  by  skin 
and  superficial  fascia,  fractures  of  this  bone  are  not  uncommonly 
compound. 


THE  REGION  OF  THE  ANKLE  AND  FOOT. 

Surface  Landmarks.— The  twomalleoli  serve  as  important 
guides  to  the  surgeon  in  operations  in  the  region  of  the  ankle- 
joint.  The  lateral  malleolus  is  the  larger  of  the  two,  and  its  tip 


478 


THE  INFERIOR  EXTREMITY 


lies  a  quarter  of  an  inch  distal  and  three-quarters  of  an  inch 
posterior  to  the  tip  of  the  medial  malleolus.  The  trochlear 
process  (peroneal  tubercle)  of  the  calcaneus  can  usually  be  felt 
one  finger's  breadth  below  the  lateral  malleolus,  but  it  is  some- 
times too  small  to  be  identified.  When  the  foot  is  actively 
everted  the  tendons  of  the  peroncei,  longus  and  brevis,  can  be 
made  out  as  they  pass  respectively  above  and  below  the 
trochlear  Drocess. 


Calcaneus 
Trochlear  proce 


Tuberosity  of  fifth  metatarsal 
Cuboid 


FIG.  140. — The  Bony  Landmarks  on  the  Lateral  Aspect  of  the  Ankle 
and  Foot. 

In  active  flexion  of  the  ankle  the  extensor  digitorum  brevis 
produces  an  elevation  on  the  lateral  part  of  the  dorsal  aspect  of 
the  foot,  and,  when  the  muscle  is  relaxed,  pseudo-fluctuation 
can  be  obtained  by  palpating  it  transversely.  The  posterior 
part  of  the  muscle  overlies  the  calcaneo- cuboid  joint  (p.  484), 
and  behind  the  joint  the  anterior  part  of  the  upper  surface  of 
the  calcaneus  can  readily  be  distinguished. 

The  tuberosity  on  the  base  of  the  fifth  metatarsal,  which  lies 
three  fingers'  breadths  in  front  of  the  lateral  malleolus,  forms 
a  prominent  landmark  on  the  lateral  border  of  the  foot.  It 


THE  REGION  OF  THE  ANKLE  AND  FOOT      479 

should  be  remembered  that  the  tuberosity  projects  in  a  backward 
direction,  and  that,  on  this  account,  in  disarticulations  (Key's 
and  Lisfranc's)  at  the  tarso-metatarsal  joint  the  knife,  entered 
on  the  lateral  side,  must  be  carried  forwards  and  medially. 

When  the  ankle  is  actively  flexed  with  the  toes  extended 
(dorsi-flexed),  the  tendons  of  the  extensor  longus  digitorwn  and 
halluds  are  rendered  very  prominent,  as  the  skin  and  superficial 
fascia  on  the  dorsum  of  the  foot  are  thin  and  the  deep  fascia  is 
not  specially  thickened  except  in  certain  situations.  When  the 


Navicular  tuberosity 
First  metatarso-cuneiform  joint 


FIG.  141. — The  Surface  Landmarks  on  the  Medial  Side  of  the  Ankle 
and  Foot. 

flexed  foot  is  actively  inverted,  the  tendon  of  the  tibialis  anterior 
can  be  traced  downwards  across  the  medial  part  of  the  anterior 
surface  of  the  ankle-joint  to  its  insertion  into  the  first  metatarsal 
and  the  adjoining  cuneiform  bone  (p.  469)  on  the  medial  side 
of  the  foot. 

The  sustentaculum  tali  lies  one  finger's  breadth  below  the 
medial  malleolus,  and  it  is  slightly  obscured  by  the  flexor 
digitorum  longus  tendon,  which  crosses  its  medial  aspect.  The 
tendon  of  the  flexor  hallucis  longus  grooves  the  plantar  surface 
of  the  sustentaculum.  The  tuberosity  of  the  navicular  lies  rather 
more  than  one  inch  in  front  of  the  sustentaculum  tali,  and  the 
interval  between  the  two  is  occupied  by  the  head  of  the  talus 
(astragalus).  This  interval  is  increased  in  flat-foot  by  the 


480  THE  INFERIOR  EXTREMITY 

downward  displacement  of  the  head  of  the  talus,  which  may 
sometimes  form  a  visible  prominence,  but  it  is  correspondingly 
diminished  in  talipes  varus  (p.  495).  The  prominent  ridge  on 
the  base  of  the  first  metatarsal  can  be  felt  at  a  point  i  J  inches  in 
front  of  the  navicular  tuberosity. 

The  first  metatarso-phalangeal  joint  lies  a  little  in  front  of  the 
centre  of  the  ball  of  the  great  toe,  while  the  others  are  placed 
one  inch  behind  the  web  of  the  toes. 


FIG.  142. — Normal  Ankle-joint  of  Child,   aged  fourteen.     Antero-posterior 
view.     Observe  the  levels  of  the  epiphyseal  lines  of  the  tibia  and  fibula. 

The  level  of  the  ankle-joint  can  be  made  out  when  the  foot  is 
passively  flexed  and  extended  alternately,  as  the  anterior  border 
of  the  distal  extremity  of  the  tibia  is  easily  felt.  When  the  foot 
is  extended,  the  anterior  part  of  the  upper  surface  of  the  body 
of  the  talus  projects  beyond  the  tibia  and  can  be  examined 
immediately  distal  to  it.  The  head  of  the  talus  can  be  felt  three- 
quarters  of  an  inch  above  and  behind  the  navicular  tuberosity. 

In  effusions  into  the  ankle-joint  the  extensor  tendons  are 
elevated  by  the  distended  capsule,  and  the  depressions  on  each 
side  of  the  tendo  calcaneus  (Achillis)  become  occluded. 


THE  REGION  OF  THE  ANKLE  AND  FOOT      481 

Ossification  of  the  Distal  Extremities  of  the  Bones  of 
the  Leg. — Secondary  centres  appear  in  the  cartilaginous  distal 
extremities  of  the  tibia  and  fibula  about  the  second  year,  and 
the  epiphyses  so  formed  unite  with  the  diaphysis  during  the 
nineteenth  year. 

As  the  fibula  projects  distally  beyond  the  tibia,  the  epiphyseal 
lines  of  the  two  bones  are  situated  at  different  levels  so  that  the 
distal  extremity  of  the  fibular  diaphysis  is  in  relation  to  the 
tibial  epiphysis  (Fig.  142),  and  therefore  to  the  joint-cavity — 
when  present  (p.  482) — of  the  distal  tibio-fibular  articulation. 
The  fibular  diaphysis  is  sometimes  intra-capsular  in  relation 
to  the  ankle-joint. 

The  Ankle- Joint. — At  this  joint  the  talus  articulates  with 
the  tibia  by  its  superior  surface  and  with  the  malleoli  on  each 
side.  The  necessary  stability  is  obtained  by  the  downward 
projection  of  the  malleoli,  which  descend  on  each  side  of  the 
talus  and  only  permit  a  slight  degree  of  lateral  movement.  The 
upper  surface  of  the  talus  is  wider  in  front  than  it  is  behind,  and 
on  this  account,  side  to  side  movements  at  the  ankle-joint  occur 
more  freely  when  the  foot  is  extended  than  when  it  is  flexed. 

The  Capsule  of  the  ankle  is  relatively  weak.  Proximally, 
it  is  attached  to  the  fibular  and  tibial  epiphyses  around  the 
margins  of  their  articular  surfaces.  Distally,  it  is  attached 
around  the  articular  surface  of  the  talus  except  on  the  anterior 
aspect  of  the  joint,  where  it  extends  on  to  the  neck  of  the  bone 
(Fig.  144);  which  is  thus  in  part  intra-capsular. 

The  synovial  membrane  lines  the  interior  of  the  capsule,  and 
anteriorly  it  is  reflected  over  the  intra-capsular  part  of  the  neck 
of  the  talus. 

The  anterior  and  posterior  ligaments  of  the  ankle  are  special 
thickenings  of  the  capsule  which  require  no  detailed  description. 
The  Deltoid  Ligament  strengthens  the  medial  part  of  the 
capsule.  It  is  narrow  at  its  proximal  attachment  to  the  medial 
malleolus,  but  widens  out  distally  and  is  attached  not  only  to 
the  talus  but  also  to  the  sustentaculum  tali,  the  plantar  calcaneo- 
navicular  ("  spring  ")  ligament  and  the  navicular  bone. 

The  Lateral  Ligament  consists  of  three  separate  bands, 
(i)  The  anterior  talo-fibular  ligament  stretches  from  the  anterior 
border  of  the  lateral  malleolus  to  the  lateral  side  of  the  body 
of  the  talus.  (2)  The  calcaneo-Jibular  ligament  is  a  cord -like 
band  which  extends  from  the  tip  of  the  malleolus  to  the  lateral 
surface  of  the  calcaneus.  (3)  The  posterior  talo-fibular  ligament 


482 


THE  INFERIOR  EXTREMITY 


passes  transversely  from  a  depression  on  the  medial  aspect  of 
the  lateral  malleolus  to  the  posterior  process  (tubercle)  of  the 
talus  (Fig.  143). 

The  Distal  Tibio-Fibular  Joint  is  usually  a  syndesmosis 

and  permits  of  practic- 
ally no  movement.  The 
two  bones  are  connected 
by  a  strong  interrosseous 
ligament  and  by  the 
inferior  transverse  liga- 
ment, which  extends 
from  the  depression  on 
the  posterior  part  of 
the  medial  surface  of  the 
lateral  malleolus  to  the 
posterior  border  of 
the  distal  extremity  of 
the  tibia.  Occasionally, 
however,  there  is  a 
joint-cavity,  which  com- 
municates freely  with 
the  cavity  of  the  ankle- 
joint. 

Anastomosis  round 
the  Ankle. — An  import- 


FIG.  143. — Frontal  Section  through  the  Ankle- 
joint,   the  Tibio-Fibular  Syndesmosis,   the    ant    anastomosis   OCCUrs 
Talo-Calcaneal   and    the    Talo-Calcaneo-  ,,  •  r     ,, 

in    the    region    of    the 


Navicular  Joints.      The  deltoid   ligament,  m     L1Jf  , 

on  the  medial  side,  and  the  posterior  talo-  ankle-joint.    Around  the 

fibular  and  the  calcaneo-fibular  ligaments,  lateral  malleolus  the  ter- 
on  the  lateral  side  are  shown  in  the  section.  7  -,       ,      f       .. 

The  strong  interosseous  talo-calcaneanliga-  mmal     and     Pirating 

ment  is  seen  forming  the  lateral  boundary  branches  of  the  peroneal 

of  the  joint  between  the  head  of  the  talus  anastomose      with      the 
and  the  sustentaculum  tali.      The  positions 
of  the  distal  epiphyseal  lines  of  the  tibia 
and  fibula  should  be  observed. 


lateral  malleolar  branch 
•of  the  anterior  tibial 
and  the  lateral  tarsal 
branch  of  the  dorsalis 
pedis.  On  the  medial 
side  of  the  ankle  the 
medial  malleolar  branch  of  the  anterior  tibial  anastomoses  with 
the  medial  calcanean  branches  of  the  lateral  plantar  artery. 

Spread   of  Tuberculous   Disease  in  the  Ankle  Region.— 
When  tuberculous  disease  originates  in  the  distal  end  of  the 


Light  blue  =  articular  cartilage. 
Striped  blue  =  ligaments. 
Green  =  periosteum. 
Red  =  synovial  membrane. 


THE  REGION  OF  THE  ANKLE  AND  FOOT      483 


diaphysis  of  the  tibia,  it  is  entirely  extra-capsular  and  extra- 
synovial  (Fig.  143),  and,  on  this  account,  the  ankle-joint  is 
rarely  involved.  The  disease  commonly  spreads  along  the 
diaphysis,  producing  diffuse  osteo-myelitis,  or  it  may  spread 
towards  the  surface  of  the  bone,  perforate  the  periosteum,  and 
affect  the  soft  parts. 

Tuberculous    disease   originating   in   the   distal   end   of  the 
fibular  diaphysis  spreads  in  a  precisely  similar  manner,  but  the 


Flexor  hallucis 
longus 

Pad  of  fat 


FIG.  144. — Sagittal  Section  of  Foot,  showing  some  of  the  Articulations. 
The  synovial  membranes  are  shown  in  red. 

1.  Flexor  hallucis  longus. 

2.  Plantar  accessory  :netatarso-phal- 

angeal  ligament. 

3.  Sesamoid  bone. 

4.  Flexor  hallucis  brevis. 

5.  Plantar  aponeurosis. 

6.  Flexor  digitorum  brevis. 


7.  Tibialis  posterior  tendon. 

8.  Flexor  digitorum  longus  tendon. 

9.  Plantar      calcaneo  -  navicular      liga- 

ment. 

10.  Quadratus  plantae. 

11.  Lateral  plantar  vessels  and  nerve. 

12.  Calcaneus. 


ankle-joint  may  be  infected  when  the  fibular  diaphysis  is 
intra-capsular  (p.  481). 

When  the  disease  commences  in  the  neck  of  the  talus,  it  may 
spread  (i)  upwards,  when  it  at  once  involves  the  synovial 
membrane  of  the  ankle-joint ;  (2)  backwards,  so  as  to  infect 
the  body  of  the  bone,  whence  it  spreads  through  the  articular 
cartilage,  either  upwards  to  the  ankle-joint  or  downwards  to 
the  talo-calcanean  joint ;  (3)  forwards,  so  as  to  infect  the  talo- 
calcaneo-navicular  joint  (Fig.  144). 

The  Joints  of  the  Foot. — The  Talo-Calcanean  Joint 
lies  immediately  below  the  ankle-joint  and  possesses  a  separate 

31  a 


484  THE  INFERIOR  EXTREMITY 

synovial  membrane.  At  this  joint  the  inferior  surface  of  the 
body  of  the  talus  articulates  with  the  upper  surface  of  the 
calcaneus  (Fig.  144). 

The  Talo-Calcaneo-Navicular  Joint  is  formed  by  the  head 
of  the  talus,,  the  posterior  surface  of  the  navicular  and  the  upper 
surface  of  the  sustentaculum  tali.  This  large  joint -cavity, 
which  is  lined  by  a  single  synovial  membrane,  is  closed  infero- 
medially  by  the  plantar  calcaneo-navicular  ligament,  and  is  shut 
off  from  the  talo-calcanean  joint  by  the  strong  interosseous  talo- 
calcanean  ligament. 

The  -plantar  calcaneo-navicular  ("  spring  ")  ligament  stretches 
from  the  anterior  border  of  the  sustentaculum  tali  to  the  plantar 
surface  of  the  navicular.  It  is  of  great  strength  so  as  to  enable 
it  to  support  the  head  of  the  talus  and  the  part  of  the  body- 
weight  which  it  transmits. 

The  Calcaneo  -  Cuboid  Joint  lies  midway  between  the 
lateral  malleolus  and  the  base  of  the  fifth  metatarsal.  It  is 
provided  with  a  separate  synovial  membrane  and  is  supported 
inferiorly  by  the  short  and  long  plantar  ligaments. 

In  Chopart's  amputation  at  the  "  transverse  tarsal  "  joint, 
the  talo-navicular  and  calcaneo-cuboid  joints  are  cut  through. 
On  the  medial  side,  the  knife  is  inserted  behind  the  navicular 
tuberosity  and  is  carried  forwards  and  laterally,  following  the 
convexity  of  the  head  of  the  talus.  On  the  lateral  side  the 
knife  is  inserted  midway  between  the  lateral  malleolus  and  the 
base  of  the  fifth  metatarsal,  and  is  carried  backwards  and 
medially,  following  the  line  of  the  calcaneo-cuboid  joint.  This 
operation  does  not  secure  a  good  bearing  surface,  as  the  talus, 
which  is  no  longer  supported  by  the  plantar  calcaneo-navicular 
ligament,  is  tilted  forwards  by  the  weight  of  the  trunk  and  the 
calcaneus  is  correspondingly  tilted  upwards  posteriorly,  despite 
division  of  the  tendo  calcaneus. 

The  joint  between  the  medial  cuneiform  and  the  first  metatarsal 
possesses  a  separate  joint  cavity,  but  the  remaining  inter-tarsal, 
tarso-metatarsal,  and  inter-metatarsal  joints  are  frequently 
lined  by  the  prolongations  of  a  single  synovial  membrane. 

In  the  amputations  of  Hey  and  Lisfranc,  the  foot  is 
disarticulated  at  the  tarso-metatarsal  articulation.  The  line 
of  the  articulation  passes  medially  and  slightly  forwards  across 
the  foot  from  the  lateral  side.  When  the  knife  is  inserted 
behind  the  tuberosity  of  the  fifth  metatarsal,  it  must  be  carried 
forwards  for  a  short  distance  before  the  joint  cavity  is  opened, 


THE  REGION  OF  THE  ANKLE  AND  FOOT      485 

and  it  can  then  be  carried  medially  and  slightly  forwards  in  the 
line  of  the  joints  until  the  second  metatarsal  is  encountered. 
The  base  of  the  second  metatarsal  projects  backwards  between 
the  medial  and  lateral  cuneiforms,  and  consequently  the  line  of 
its  articulation  with  the  second  cuneiform  is  posterior  to  the 
other  tarso -metatarsal  joints.  The  knife  is  then  inserted  on 
the  medial  side  of  the  foot  just  behind  the  base  of  the  first 
metatarsal,  and  is  carried  laterally  and  slightly  backwards 
through  the  first  joint  until  it  is  again  obstructed  by  the  base 
of  the  second  metatarsal.  After  division  of  the  dorsal  cuneo- 
metatarsal  ligaments,  an  attempt  is  made  to  flex  the  metatarsus 
on  the  tarsus.  This  process  puts  on  the  stretch  the  strong 
interosseous  ligaments  which  connect  the  base  of  the  second 
metatarsal  to  the  medial  and  lateral  cuneiforms,  and  after  they 
have  been  divided  by  cutting  backwards,  the  disarticulation 
may  be  completed  by  cutting  through  the  plantar  cuneo- 
metatarsal  ligaments.  Instead  of  disarticulation,  the  base  of 
the  second  metatarsal  may  be  sawn  across  ;  or  the  medial 
cuneiform  may  be  sawn  through  on  a  level  with  the  second 
cuneo-metatarsal  joint,  and  the  base  of  the  second  metatarsal 
can  then  be  disarticulated  by  division  of  the  strong  interrosseous 
ligament  which  connects  it  to  the  lateral  cuneiform  bone. 

The  intertarsal  or  tarso-metatarsal  joints  may  be  infected 
with  tuberculous  disease  from  a  focus  in  one  of  the  tarsal  or 
metatarsal  bones,  as  the  disease  requires  to  erode  only  the 
articular  cartilage. 

Injuries  in  the  Region  of  the  Ankle  -  Joint.— 
Injuries  in  this  region  commonly  follow  falls  or  twists  in  which 
the  weight  of  the  body  is  transmitted  along  a  line  which  is 
either  lateral  or  medial  to  the  usual  axis  (p.  463).  As  a  result 
the  foot  is  over-inverted  or  over-everted,  and  a  slight  degree  of 
adduction  or  abduction  may  be  present.  The  precise  nature 
of  the  injury  will  depend  on  the  position  into  which  the  foot  is 
forced  by  the  violence,  but  it  must  be  remembered  that,  in 
children,  a  diastasis  may  occur  instead  of  a  fracture.  These 
injuries  almost  always  involve  the  ankle-joint,  and  the  consequent 
swelling  tends  to  obscure  the  subcutaneous  bony  points. 

Sprains  of  the  Ankle  usually  occur  following  over-inversion 
of  the  foot.  The  anterior  talo-fibular  and  sometimes  the 
calcaneo-fibular  ligaments  (anterior  and  middle  fasciculi  of  the 
external  lateral  ligament)  are  torn,  and  in  severe  cases  the 
anterior  part  of  the  capsule  also  is  ruptured.  Tenderness  is 

31  b 


486  THE  INFERIOR  EXTREMITY 

experienced  on  palpation  over  the  attachments  of  these  ligaments 
(p.  481)  but  no  pain  is  elicited  on  examination  of  the  subcutaneous 
surface  of  the  fibula.  Swelling  and  discoloration  are  often 
more  marked  than  they  are  when  a  fracture  is  present. 

A  somewhat  similar  condition  results  from  over-eversion  of 
the  foot,  but  in  this  case  tenderness  is  experienced  over  the 
attachments  of  the  deltoid  ligament  (p.  481). 

Pott's  Fracture. — Fracture  of  the  distal  part  of  the  fibula 
is  a  common  accident,  as  the  region  is  frequently  subjected  to 
violence,  and  the  ligaments  of  the  tibio-fibular  syndesmosis 
(p.  482)  are  stronger  than  the  bone.  The  term  "  Pott's  Fracture" 
includes  two  distinct  varieties  of  injury :  (a)  fracture  of  the 
distal  part  of  the  fibula  together  with  injury  of  the  deltoid 
ligament  or  medial  malleolus,  and  (b)  fractures  of  the  distal 
extremity  of  the  tibia,  together  with  tearing  of  the  lateral 
ligament  of  the  ankle  or  fracture  of  the  lateral  malleolus. 

(a)  In  violent  eversion  of  the  foot,  the  deltoid  (internal 
lateral)  ligament  is  overstretched  and  may  either  give  way  or 
tear  off  the  medial  malleolus.     In  children,  a  diastasis  of  the 
tibial  epiphysis  may  result.     If  the  violence  continues  to  act 
the  lower  part  of  the  lateral  surface  of  the  talus  is  forced  against 
the  lateral  malleolus  and  the  distal  part  of  the  fibular  shaft  gives 
way,  unless  the  powerful  ligaments  of  the  distal  tibio-fibular 
joint  are  torn  through.    The  latter  condition  does  occasionally 
occur,  and  is  indicated  by  a  great  increase  in  the  width  of  the 
ankle.    In  these  circumstances  the  talus  may  be  dislocated 
upwards  between  the  tibia  and  fibula  (Dupuytren's  fracture). 

(b)  In  violent  inversion  of  the  foot,  the  upper  part  of  the 
lateral  surface  of  the  talus  is  tilted  laterally  and  downwards 
against  the  lateral  malleolus  and  the  lateral  ligament  gives  way, 
or  the  fibula  fractures   proximal  to  the   tibio  -  fibular  joint. 
Continuance  of  the  violence  forces  the  medial  surface  of  the 
talus  upwards  and  medially  against  the  medial  malleolus,  which 
gives  way,  often  breaking  off  an  irregular  fragment  from  the 
distal  extremity  of  the  tibia. 

Fractures  in  this  region  may  be  associated  with  incomplete 
dislocations  of  the  foot. 

Dislocation  of  the  Talus  is  rare  and  is  often  compound. 

When  deformities  in  this  region  are  being  corrected,  the 
knee  should  be  passively  flexed  to  relax  the  tension  of  the 
muscles  of  the  calf.  Subsequently  the  foot  should  be  kept  at 
right  angles,  for  in  this  position  the  widest  part  of  the  talus 


THE  REGION  OF  THE  ANKLE  AND  FOOT      487 

occupies  the  interval  between  the  two  malleoli,  and  contracture 
of  the  tendo  calcaneus  is  unlikely  to  occur.  It  is  wiser  to  err 
on  the  side  of  inversion  rather  than  eversion,  as  in  the  latter 
case  flat-foot  may  subsequently  develop,  and  to  avoid  this 
sequela,  care  must  be  exercised  to  see  that  the  medial  margin 
of  the  hallux,  the  medial  malleolus  and  the  medial  border  of  the 
patella  are  all  in  the  same  straight  line. 

Surgical  Approach  to  the  Ankle  -  Joint.  —  In 
arthrotomy,  arthrodesis,  excision  of  the  joint  or  removal  of  the 
talus,  the  best  approach  is  obtained  by  means  of  Kocher's  lateral 
J-shaped  incision,  with  or  without  some  slight  modification. 
This  incision  begins  behind  the  fibula  and  extends  below  the 
lateral  malleolus  to  the  trochlear  process  (peroneal  tubercle), 
being  placed  above  the  nervus  suralis  and  the  small  saphenous 
vein.  From  this  point  it  curves  gently  forwards  to  end  a  little 
behind  the  insertion  of  the  peronseus  tertius  (p.  471).  The  flap 
thus  outlined,  which  consists  of  skin,  fascia  and  periosteum  of 
the  lateral  malleolus,  is  dissected  forwards  off  the  peronaei  and 
the  malleolus,  while  below,  after  division  of  the  cruciate  ligament, 
it  is  dissected  off  the  anterior  talo-fibular  ligament  (p.  481),  the 
anterior  ligament  of  the  ankle  and  the  extensor  digitorum 
brevis.  The  whole  flap  is  then  retracted  to  the  medial  side 
together  with  the  extensor  tendons.  After  the  retinacula  have 
been  split  and  the  peroneal  tendons  divided,  the  three  parts  of 
the  lateral  ligament  of  the  ankle  (p.  481),  and  the  weak  anterior 
and  posterior  ligaments  are  cut  through  and  the  foot  is  forcibly 
dislocated  by  over-inversion.  During  this  process  the  medial 
malleolus  may  break,  but  this  accident  is  unimportant,  as  the 
deltoid  ligament  remains  intact  and  the  surfaces  can  subsequently 
be  re-opposed. 

By  this  method,  a  complete  view  of  the  interior  of  the  joint 
is  obtained,  and  the  diseased  synovial  membrane  can  be  entirely 
removed  along  with  the  anterior  and  posterior  ligaments,  but 
care  must  be  taken  not  to  injure  the  anterior  or  posterior  tibial 
arteries  as  they  lie  in  relation  to  the  joint  (pp.  472  and  476). 

Excision  of  the  Talus. — If  the  arthrotomy  shows  that  the 
disease  originated  in  the  talus,  this  bone  may  be  excised 
completely.  The  posterior  part  of  the  extensor  digitorum 
brevis  is  elevated,  and  the  talo-navicular  joint  is  opened.  The 
head  of  the  talus  can  be  drawn  upwards,  and  when  the  talo- 
calcanean  interosseous  ligament  is  cut  through,  the  bone  is 
held  only  by  the  attachment  of  the  deltoid  ligament  to  its  medial 


488  THE  INFERIOR  EXTREMITY 

surface  (p.  481).  The  removal  of  the  talus  opens  both  the 
talo-calcanean  and  the  talo-calcaneo-navicular  joint-cavities, 
and  if  the  synovial  membrane  which  lines  them  is  infected,  it 
must  be  removed. 

After  excision  of  the  talus,  the  sustentaculum  tali  may  be 
removed^  and  the  calcaneus  may  be  further  trimmed  till  it  can 
be  fitted  in  between  the  malleoli.  When  this  is  carried  out,  the 
lateral  malleolus  projects  too  far,  and  therefore  requires  to  be 
shortened. 

Before  the  wound  is  finally  closed,  the  peroneal  tendons  are 
sutured,  and  the  retinacula  are  stitched  over  them  again. 

Arthrodesis  of  the  Ankle  -  Joint  is  rarely  followed  by 
completely  satisfactory  results,  because  the  necessary  removal 
of  the  articular  cartilage  decreases  the  size  of  the  talus  while 
increasing  the  size  of  the  cavity  into  which  it  is  to  be  received. 
This  disadvantage  may  be  minimised  by  inserting  a  large  nail 
in  an  upward  direction  through  the  calcaneus  and  talus  into 
the  tibia,  the  foot  meanwhile  being  maintained  at  right  angles  ; 
when  the  nail  is  removed  at  the  end  of  three  weeks,  the  limb  is 
put  up  in  a  plaster  case. 

The  Calcaneus  (Os  Calcis). — Tuberculous  disease  may  not 
infrequently  originate  in  the  body  of  the  calcaneus  close  to  the 
epiphyseal  line,  and  may  spread  (i)  upwards  and  forwards,  to 
penetrate  the  articular  cartilage  and  infect  the  talo-calcanean 
joint ;  (2)  medially,  through  the  periosteum  to  infect  the 
synovial  sheaths  of  the  tendons  of  the  tibialis  posterior,  etc. 
(p.  475) ;  (3)  laterally,  through  the  periosteum,  to  infect  the 
peroneal  tendon  sheaths  (p.  473).  Early  recognition  by 
radiograms  is  important  in  order  that  these  complications  may 
be  prevented. 

The  surgical  approach  to  the  calcaneus  is  obtained  by  means, 
of  a  lateral  or  a  medial  flap  operation.  The  incisionjies  below 
the  level  of  the  tendons  and  the  flap  includes  all  the  soft  parts 
and  the  periosteum.  In  the  child,  since  the  body  of  the  bone 
is  not  completely  ossified,  a  thin  layer  of  its  cartilaginous  surface 
is  elevated  with  the  periosteum.  The  focus  may  then  be  gouged 
out  and  the  flap  replaced. 

In  more  advanced  cases,  where  freer  access  is  desired,  the 
incision  begins  behind  the  tuberosity  of  the  fifth  meiatarsal 
and,  passing  backwards  round  the  heel  below  the  tendo  calcaneus, 
ends  on  the  medial  aspect  slightly  in  front  of  the  medial  malleolus. 
A  large  flap,  consisting  of  soft  parts,  periosteum,  and  cartilage, 


THE  REGION  OF  THE  ANKLE  AND  FOOT      489 

can  then  be  turned  down  from  the  lateral,  posterior,  and  medial 
aspects  of  the  calcaneus. 

Ossification  of  the  Tarsus. — At  birth,  ossific  centres  are 
present  in  the  calcaneus,  the  talus  and  the  cuboid.  The  lateral 
cuneiform  begins  to  ossify  during  the  first  year,  the  middle 
cuneiform  during  the  second  year,  and  the  medial  cuneiform 


FIG.  145. — Normal  Ankle-joint.      Lateral  View. 
calcanean  epiphysis. 


Observe  the 


and  the  navicular  during  the  third  or  fourth  year.  A  secondary 
centre  appears  in  the  cartilaginous  posterior  extremity  of  the 
calcaneus  during  the  eighth  year,  and  forms  an  epiphysis  which 
unites  with  the  body  of  the  bone  between  the  ages  of  sixteen  and 
twenty.  A  separate  centre  for  the  posterior  process  (external 
tubercle)  of  the  talus  is  sometimes  present,  and  it  may  remain 
separate,  being  then  known  as  the  os  trigonum  (Fig.  146). 

Fractures  of  the  tarsal  bones  may  occur  when  the  patient, 


490 


THE  INFERIOR  EXTREMITY 


after  falling  from  a  height,  lands  upon  his  feet.    They  commonly 
involve  either  the  talus  or  the  calcaneus. 

The  neck  of  the  talus  may  be  fractured  transversely,  or  the 
body  of  the  bone  may  be  crushed  between  the  calcaneus  and 


FIG.  146. — Avulsion  Fracture  of  the  Calcaneus.  The  fragment  has  been 
fixed  in  position  with  a  screw.  Note  the  increased  density  of  the  shadow 
caused  by  the  superimposed  lateral  malleolus.  It  partially  obscures  the 
os  trigonum  tarsi,  which  is  present  in  this  case. 

the'  tibia.    The  condition  is  always  accompanied  by  considerable 
limitation  of  movement  at  the  ankle-joint. 

Fracture  of -the  calcaneus,  which  is  the  commonest  fracture 
of  the  tarsus,  is  usually  comminuted  and  is  often  bilateral.  If 
there  is  little  comminution,  the  fracture  may  be  overlooked, 
unless  X-rays  are  employed,  as  the  collateral  ligaments  of  the 
ankle  and  the  tendons  in  relation  to  the  calcaneus  retain  the 


THE  REGION  OF  THE  ANKLE  AND  FOOT      491 

fragments  in  fair  position.  It  is  important  that  the  injury 
should  be  recognised  since  flat-foot  may  result  unless  proper 
treatment  is  carried  out.  When  the  fragments  have  been  moulded 
into  position,  the  foot  is  put  up  at  right  angles  and  slightly 
inverted. 

Fracture  of  the  sustentaculum  tali  and  avulsion  of  the  postero- 
superior  part  of  the  calcaneus  are  rare  injuries  (Fig.  146). 

In  the  examination  of  radiograms  of  the  tarsus,  the  presence 
of  the  calcanean  epiphysis  and  the  occasional  os  trigonum 
(p.  489)  must  be  borne  in  mind. 

Fractures  of  the  metatarsals  are  difficult  to  recognise  as  the 
oedema  may  be  considerable,  and  there  is  little  or  no  displace- 
ment, owing  to  the  way  in  which  the  bones  are  bound  together 
in  the  transverse  arch  of  the  foot.  The  prominent  base  of  the 
fifth  metatarsal  may  be  fractured  when  the  patient  falls  heavily 
on  the  inverted  foot  (Jones). 

The  Deep  Fascia  of  the  sole  of  the  foot  is  termed  the  plantar  aponeurosis. 
Like  the  palmar  aponeurosis  (p.  82),  it  consists  of  a  strong  central  and  two 
weak  collateral  parts.  The  central  portion  is  attached  posteriorly  to  the 
calcanean  tuberosity,  and  anteriorly  it  divides  into  five  slips,  which  are 
connected  to  the  fibrous  flexor  sheaths  of  the  toes  (cf.  palm  of  hand,  p.  83). 
It  is  the  central  portion  of  the  plantar  aponeurosis,  which  normally  helps  to 
support  the  longitudinal  arch  of  the  foot,  and  it  is  much  shortened  in  pes 
cavus  and  in  some  of  the  varieties  of  talipes. 

The  weak,  medial  part  of  the  plantar  aponeurosis  covers  the  abductor 
hallucis,  which  extends  from  the  calcanean  tuberosity  to  the  medial  side  of 
the  base  of  the  first  phalanx  of  the  hallux. 

Owing  to  the  density  of  the  central  part  of  the  plantar  aponeurosis, 
swelling  first  becomes  apparent  on  the  dorsum  of  the  foot  in  inflammatory 
conditions  of  the  sole  or  of  the  articulations  (cf.  palm  of  hand,  p.  82). 

The  small  muscles  of  the  sole  of  the  foot  are  of  less  importance  than  the 
corresponding  muscles  in  the  palm  of  the  hand,  as  the  foot  is  primarily 
required  to  be  a  stable  support  for  the  body  weight,  and  the  movements  of 
the  individual  toes,  therefore,  are  of  less  consequence. 

The  medial  plantar  nerve  (L.  4,  5,  and  S.  i)  arises  from  the  tibial  nerve 
under  cover  of  the  laciniate  ligament  (p.  471),  and  runs  forwards  with  the 
medial  plantar  artery.  It  corresponds  to  the  median  nerve  in  the  palm  of 
the  hand,  and,  though  it  supplies  few  muscles,  it  supplies  a  large  cutaneous 
area,  including  the  plantar  aspects  of  the  medial  three  toes  and  the  tibial 
side  of  the  fourth  toe. 

The  lateral  plantar  nerve  (S.  i  and  2)  corresponds  to  the  ulnar  nerve  in 
the  palm  of  the  hand  (p.  85).  It  arises  from  the  tibial  nerve  under  cover 
of  the  laciniate  ligament,  and  accompanies  the  lateral  plantar  artery  and  the 
plantar  arch.  It  supplies  most  of  the  muscles  of  the  sole,  the  skin  of  the 
lateral  part  of  the  sole,  and  the  plantar  aspects  of  the  fifth  toe  and  the  fibular 
side  of  the  fourth  toe 

At  the  distal  border  of  the  laciniate  ligament  the  posterior  tibial  artery 
divides  into  the  lateral  and  medial  plantar  arteries.  The  medial  plantar, 
which  is  usually  a  small  vessel,  passes  forwards  between  the  abductor  hallucis 


492  THE  INFERIOR  EXTREMITY 

and  the  flexor  digitorum  brevis,  and  its  terminal  branches  join  the  digital 
arteries. 

The  lateral  plantar  artery  runs  forwards  and  laterally  towards  the  base  of 
the  fifth  metatarsal,  where  it  bends  sharply  medially,  and  becomes  the  plantar 
arch.  The  arch  lies  on  the  bases  of  the  middle  three  metatarsals,  and  is 
completed  at  the  posterior  end  of  the  first  inter-metatarsal  space,  where  it 
is  joined  by  the  dorsalis  pedis  artery. 

Gangrene  of  the  Foot. — When  senile  gangrene  is  due  to 
gradual  obliteration  of  the  small  arteries  of  the  foot,  it  begins 
at  the  periphery  and  spreads  in  a  proximal  direction.  The 
pathological  process  tends  to  be  delayed,  and  may  even  come 
to  a  sudden  stop,  on  the  distal  side  of  the  large  joints.  The 
position  of  these  lines  of  demarcation  is  determined  by  the 
anastomoses,  which  occur  round  the  ankle  (p.  482),  the  knee 
(p.  445),  and  the  hip  (pp.  416  and  418). 

On  the  other  hand,  when  gangrene  is  due  to  obstruction  of 
one  of  the  main  arterial  trunks  by  an  embolus,  its  onset  is  sudden 
and  a  large  area  is  rapidly  involved. 

The  Architecture  of  the  Foot  is  so  planned  that  the 
weight  of  the  body  may  be  equally  distributed  over  the  bearing 
surface.  Under  normal  conditions  the  foot  forms  a  tripod, 
the  points  of  which  are  the  calcaneus  and  the  heads  of  the  first 
and  fifth  metatarsal  bones.  To  a  much  lesser  extent,  the  heads 
of  the  middle  three  metatarsals  and  the  lateral  border  of  the 
foot  help  to  support  the  body-weight.  This  arrangement  is 
maintained  by  the  presence  of  two  intersecting  arches,  of  which 
one  is  longitudinal  and  the  other  transverse.  Each  is  supported 
by  ligaments,  muscles  and  tendons,  which  render  it  somewhat 
elastic.  On  this  account  the  arches  flatten  out  slightly  when 
the  weight  of  the  body  is  borne  upon  the  feet  and  contract  again 
as  soon  as  the  weight  is  removed. 

The  Longitudinal  Arch  is  constituted  by  the  medial  border 
of  the  foot,  and  its  keystone  is  formed  by  the  head  of  the  talus. 
The  short  posterior  limb  of  the  arch  is  formed  by  the  calcaneus, 
while  the  navicular,  cuneiforms,  and  medial  three  metatarsals 
constitute  the  longer  anterior  limb.  The  head  of  the  talus  is 
supported  by  the  plantar  calcaneo- navicular  ("spring") 
ligament,  which  extends  between  the  sustentaculum  tali  and 
the  navicular  (Fig.  144).  This  ligament  is  supported,  in  its 
turn,  by  the  strong  tendons  of  the  tibialis  posterior,  the  flexor 
digitorum  longus  and  the  flexor  hallucis  longus,  which  are 
related  to  its  medial  border  and  plantar  aspect.  The  two  flexor 
tendons  cross  one  another  in  the  region  of  the  plantar  calcaneo- 


THE  REGION  OF  THE  ANKLE  AND  FOOT      493 


navicular  ligament  and  the  tendinous  sling  which  they  form 
renders  additional  support.  Further  the  longitudinal  arch 
is  strengthened  by  the  plantar  aponeurosis  and  the  abductor 
hallucis,  which  connect  the  bases  of  its  two  limbs  (Fig.  144). 

The  principal  Transverse  Arch  is  placed  at  the  level  of  the 
distal  row  of  the  tarsus  and  the  bases  of  the  metatarsal  bones. 
It  is  maintained  by  the  plantar  inter-tarsal  and  tarso-metatarsal 
ligaments,,  while  the  tendon  of  the  peronseus  longus  stretches 
across  the  arch  like  a  bow-string  and  serves  to  approximate  its 
extremities  (Fig.  147).  Additional  support  is  obtained  from  the 
tendinous  sling  formed  by  the  crossing  of  the  flexor  longus 


Second  cuneiform 
Dorsalis  pedis  a. 
First  cuneiform     I 


Third  cuneiform 

Fibrous  sheath  of  peronaeus  longus 
Peronaus  longus  tendon 


Cuboid 


Abductor 
digiti  quinti 


i  Lateral  plantar  a. 

Abductor  hallucis  |  I       |         Lateral  plantar  n. 

Flexor  hallucis  brevis  |      Quadratus  plantae 

Flexor  hallucis  longus  tendon  Flexor  digitorum  brevis 

Medial  plantar  a.  |  Flexor  digitorum  longus  tendon 
Medial  plantar  n. 

FIG.  147. — Transverse  Section  through  the  Foot,  to  show  the  Transverse 
Arch  of  the  Foot  and  the  Peronaeus  Longus  Tendon. 

digitorum  and  hallucis  tendons,  and  from  the  additional  slips 
of  insertion  of  the  tibialis  posterior  (p.  475),  which  tend  to 
contract  the  arch. 

Fiat-Foot. — Loss  of  tone  in  the  muscles  which  support  the 
arches  of  the  foot  throws  an  increased  strain  upon  the  supporting 
ligaments  and  constitutes  the  first  stage  in  the  development  of 
flat-foot.  At  this  period  treatment  must  be  directed  to  the 
weakened  muscles,  or  the  ligaments  will  gradually  stretch, 
giving  rise  to  pain  and  aching  over  their  attachments.  In  the 
second  stage  both  arches  give  way,  the  longitudinal  flattening 
being  the  more  noticeable.  The  head  of  the  talus  sinks 
downwards,  forwards  and  medially  so  as  to  increase  the  interval 
between  the  navicular  tuberosity  and  the  sustentaculum  tali ; 


494  THE  INFERIOR  EXTREMITY 

and  produces  a  prominence  on  the  medial  border  of  the  foot  in 
front  of  the  medial  malleolus.  The  downward  displacement 
of  the  talus  is  accompanied  by  lateral  deviation  of  the  foot, 
and  the  body-weight  is  carried  on  the  collapsed  longitudinal 
arch. 

Deformities  of  the  Foot.— Talipes  may  be  either  a 
congenital  or  an  acquired  deformity  and  may  affect  one  or  both 
feet.  In  Congenital  Talipes  the  foot  develops  in  the  faulty 
attitude  and  the  bones  are  therefore  modified  in  shape,  while 
some  of  the  soft  structures  are  lengthened  and  others  are 
shortened.  In  Acquired  Talipes,  which  usually  results  from 
acute  anterior  poliomyelitis  and  occasionally  from  cerebral 
palsy  or  nerve  injuries,  the  attitude  of  the  foot  depends  on  the 
over-action  of  some  muscle  or  muscles  following  parsesis  or 
paralysis  and  atrophy  of  its  antagonists. 

Four  primary  deformities  are  recognised:  (i)  Talipes  Equinus, 
in  which  the  heel  is  raised  and  the  toes  are  pointed  ;  (2)  Talipes 
Calcaneus,  in  which  the  foot  is  dorsi-flexed  and  the  long  axis 
of  the  calcaneus  becomes  nearly  vertical ;  (3)  Talipes  Varus, 
in  which  the  foot  is  inverted  ;  (4)  Talipes  Valgus,  in  which  the 
foot  is  everted.  Combinations  of  these  primary  deformities 
may  occur,  including  Talipes  Equino-varus — by  far  the 
commonest  of  all  the  varieties  of  talipes  —  Equino-valgus, 
Calcaneo-varus  and  Calcaneo-valgus. 

(1)  Talipes    Equinus. — When  the   condition   is    congenital, 
the  muscles  of  the  posterior  compartment  of  the  leg  and  the 
plantar  aponeurosis  are  shortened   secondarily  to   the   faulty 
position.     When  the  condition  is  acquired,  it  is  caused  by  the 
tonus  of  the  muscles  of  the  posterior  compartment,  which  are 
unopposed  owing  to  paralysis  or  parsesis  of  the  muscles  of  the 
anterior  compartment  of  the  leg.     All  the  anterior  muscles  are 
not  necessarily  involved  and  one  or  more  of  them  may  escape. 

(2)  Talipes  Calcaneus. — When  the  condition  is  congenital, 
the  tendons  of  the  muscles  of  the  anterior  compartment  of  the 
leg  are  shortened,  while  the  muscles  of  the  posterior  compartment 
are  overstretched.     When  the  condition  is  acquired,  it  is  caused 
by  the  tonus  of  the  muscles  of  the  anterior  compartment,  which 
are  unopposed  owing  to  paralysis  of  the  posterior  muscles.     As 
in  the  other  varieties  of  acquired  talipes,  the  degree  of  the 
deformity  depends  on  the  extent  of  the  paralysis,  the  condition 
being  most  marked  when  both  the  superficial  and  the  deep 
muscles  are  affected. 


THE  REGION  OF  THE  ANKLE  AND  FOOT      495 

(3)  Talipes  Yarns. — When  the  condition  is  congenital,  the 
tendons  of  the  tibialis  anterior  and  posterior  are  shortened,  and 
the  distal  part  of  the  tibial  diaphysis  is  twisted  slightly  in  a 
medial  direction.    When  the  condition  is  acquired,  it  results 
from  the  tonus  of  the  tibialis  anterior  following  paralysis  of  the 
peronaeus  longus  or  brevis,  or  of  both  these  muscles. 

(4)  Talipes  Valgus. — In  the  congenital  variety  the  peronsei, 
longus,  brevis,  and  tertius,  are  shortened  while  the  two  tibiales 
are  overstretched.      The  acquired  variety  is  due  to  paralysis 
of  both  the  tibialis  anterior  and  the  tibialis  posterior. 

In  the  combined  varieties,  the  muscles  of  more  than  one 
compartment  are  involved.  Thus,  in  acquired  talipes  equino- 
varus,  the  peronsei  are  affected  together  with  one  or  more 
muscles  of  the  anterior  compartment.  The  highest  degree  of 
the  deformity  is  produced  when  all  the  muscles  of  both  com- 
partments are  paralysed. 

In  congenital  talipes,  the  treatment  should  be  based  on  the 
degree  of  the  deformity.  In  minor  deformities,  methodical 
manipulations,  which  tend  to  overcorrect  the  faulty  position, 
and  possibly  the  use  of  a  light  splint,  may  be  sufficient.  When 
the  deformity  is  more  pronounced,  the  manipulations  must  be 
more  vigorous,  and  tenotomy  of  the  shortened  structures 
may  be  necessary  before  the  foot  can  be  wrenched  into  better 
position.  In  the  worst  cases  operative  interference,  such  as 
excision  of  the  talus  or  the  removal  of  a  wedge-shaped  portion 
from  the  tarsus  (cuneiform  tarsectomy),  alone  will  produce 
correct  alignment. 

Cuneiform  Tarsectomy. — The  position  of  the  wedge  of 
bone  removed  in  cuneiform  tarsectomy  depends  on  the  nature 
of  the  deformity.  In  talipes  equino-varus ,  the  base  of  the  wedge 
is  on  the  lateral  border  of  the  foot.  The  incision,  which  divides 
the  nervus  suralis  and  the  small  saphenous  vein,  is  carried 
backwards  and  laterally  from  the  prominent  head  of  the  talus 
to  the  calcaneus.  The  skin  and  fasciae  are  undercut,  and  this 
step  exposes  the  medially  displaced  extensor  tendons  at  the 
medial  extremity  of  the  wound  and  the  extensor  digitorum 
brevis  at  the  lateral  extremity.  The  lateral  part  of  the  cruciate 
ligament  (p.  470)  is  divided  and  turned  medially,  together  with 
the  extensor  digitorum  brevis,  which  is  elevated  from  the 
calcaneus.  The  extensor  tendons  are  retracted,  and  a  sharp 
gouge  is  thrust  horizontally  through  the  lateral  surface  of  the 
calcaneus  into  the  talo-navicular  joint.  The  gouge  is  next 


496 


THE  INFERIOR  EXTREMITY 


inserted  at  the  cubo-metatarsal  joint  and  carried  medially 
through  the  cuneiform  bones  to  the  medial  border  of  the  foot. 
Thereafter  the  wedge  is  removed;  and  if  sufficient  bone  has  been 
resected,  the  two  portions  of  the  foot  can  be  brought  together 
without  any  stretching  of  soft  parts. 

In  order  to  correct  the  "  in-toeing/'  the  abductor  hallucis 
(p.  491)  may  be  excised  through  a  linear  incision  on  the  medial 
side  of  the  foot.  Division  or  lengthening  of  the  tendo  calcaneus 
(p.  475)  completes  the  operation. 

It  must  be  remembered  that  many  of  the  muscles  which  are 
involved  at  first  in  acute  anterior  poliomyelitis  may  subsequently 
recover;  and  on  this  account  steps  must  be  taken  to  prevent 
the  temporarily  paralysed  muscles  from  being  overstretched  by 
their  unaffected  antagonists.  Deformities  which  result  from 
the  permanent  paralysis  of  some  muscle  or  muscles  may  be 
diminished  by  operative  treatment. 

Arthrodesis  is  restricted  to  cases  of  widespread  paralysis 
with  flail  joints. 

When  the  paralysis  is  more  limited;  nerve-anastomosis,  a 
practice  as  yet  in  process  of  development;  or  tendon  trans- 
plantation, may  be  carried  out.  In  the  latter  operation;  either 
the  whole  or  part  of  the  tendon  of  an  unaffected  muscle  may  be 
transplanted  into  the  tendon  of  one  of  the  paralysed  muscles, 
or  it  may  be  inserted  subperiosteally  to  a  fresh  attachment  so 
as  to  restore  the  muscular  balance  of  the  foot. 

The  following  table  shows  the  position  in  which  tenotomy 
of  the  various  tendons  can  be  carried  out  most  conveniently  : 


Tendon. 


Position  of  Incision. 


Tibialis  Anterior. 
Tibialis  Posterior. 
Tendo  Calcaneus. 

Peronsei       (Longus       and 

Brevis). 
Extensor  Hallucis  Longus. 


Extensor  Digitorum  Longus 
and  Peronaeus  Tertius. 


At  lateral  side  of  tendon,  just  anterior  to 

the  tuberosity  of  the  navicular. 
At  medial  side  of  tendon,  proximal  to  the 

medial  malleolus. 
i£  inches  (in  the  child,  £  inch)  proximal  to 

its  insertion. 
At  lateral  side  of  tendons  proximal  to  tip 

of  lateral  malleolus. 
At  lateral  side  of  tendon  (to  avoid  injuring 

the    dorsalis    pedis),    and    opposite    the 

tuberosity  of  the  navicular. 
At  medial  side  of  tendons  (to  avoid  injuring 

the  anterior  tibial  vessels),  either  at  the 

ankle-joint  or  one  inch  proximal  to  it. 


THE  REGION  OF  THE  ANKLE  AND  FOOT      497 

In  each  case,  after  the  incision  has  been  made,  a  blunt-pointed 
tenotome  is  introduced  between  the  tendon  and  the  bone  on 
which  it  lies.  The  tendon  is  then  stretched  across  the  edge  of 
the  knife  and  divided. 

The  plantar  aponeurosis  may  be  divided  through  a  number 
of  small  incisions,  made  in  the  neighbourhood  of  the  tightened 
bands. 

Ossification  of  the  Metatarsal  Bones  and  Phalanges. — 
Each  of  the  metatarsals  and  each  of  the  phalanges  possesses  a 
single  epiphysis.  In  the  cases  of  the  second,  third,  fourth,  and 
fifth  metatarsals,  the  epiphysis  forms  the  rounded  head  of  the 
bone.  It  appears  during  the  third  or  fourth  years  and  unites 
with  the  diaphysis  at  eighteen.  In  the  case  of  the  first 
metatarsal,  the  epiphysis  forms  the  base  of  the  bone.  It 
appears  during  the  second  or  third  years  and  joins  the  diaphysis 
at  eighteen. 

The  ossification  of  the  phalanges  is  similar  to  that  of  the  first 
metatarsal.  The  epiphyses,  which  appear  at  the  fourth  year 
and  fuse  at  eighteen,  form  the  proximal  extremities. 

It  may  be  noted  that  the  first  metatarsal  resembles  the 
phalanges  still  further  in  the  frequency  with  which  it  is  attacked 
by  tuberculous  disease. 

Tuberculous  disease  of  the  metatarsals  commences  near  the 
centre  of  the  diaphysis  as  an  osteo-myelitis,  probably  owing  to 
the  fact  that  the  nutrient  artery,  on  entering  the  bone,  at  once 
divides  into  a  leash  of  small  vessels  and  not  into  large  ascending 
and  descending  branches,  as  it  does  in  the  long  bones  proper. 

The  first  metatarsal  may  be  resected  subperiosteally  through 
a  dorso-medial  incision,  which  at  once  exposes  the  bone.  After 
the  periosteum  has  been  freely  elevated,  the  diaphysis  is  divided 
near  the  head  and  can  be  wrenched  away  from  the  epiphyseal 
cartilage,  which  is  left  behind  with  the  basal  epiphysis.  In  this 
way  the  surgeon  avoids  opening  into  the  tarso-metatarsal  and 
the  metatarso-phalangeal  joints. 

The  same  method  may  be  followed  in  resection  of  any  of  the 
other  metatarsals,  save  that  the  diaphysis  must  be  divided  near 
the  base  and  then  wrenched  away  from  the  distal  epiphysis 

(P-  93)- 

In  sub-periosteal  resection  of  the  proximal  phalanges  of  the 

lateral  four  toes,  a  dorso-lateral  incision  is  employed  to  avoid 
injuring  the  tendons  of  the  lumbricals,  which  are  inserted  into 
the  tibial  sides  of  the  phalangeal  bases. 

32 


498  THE  INFERIOR  EXTREMITY 

In  Hallux  Valgus  the  great  toe  becomes  excessively 
adducted  and  overrides  or  underlies  the  second  toe.  The 
condition  is  caused  by  the  wearing  of  faultily  made  boots  or 
shoes,  which  in  addition  to  being  too  short,  have  the  point  of 
the  toe  in  line  with  the  third  instead  of  in  line  with  the  first 
digit.  The  toes,  therefore,  are  approximated  to  one  another 
in  the  narrow  toe  of  the  boot.  Once  the  normal  alignment  of 
the  great  toe  is  altered,  the  distortion  is  increased  by  the  action 
of  the  long  flexor  and  extensor  tendons.  In  pronounced  cases, 
these  tendons  and  the  lateral  metatarso-phalangeal  ligament 
become  shortened  and  the  medial  part  of  the  head  of  the  first 
metatarsal  is  rendered  unduly  prominent.  A  bursa,  which 
subsequently  develops  into  a  bunion,  is  formed  over  the  bone. 

The  condition  may  be  improved  by  the  resection  of  the 
distal  two-thirds  of  the  head  of  the  first  metatarsal.  A  semi- 
lunar  incision,  the  base  of  which  is  directed  towards  the  sole, 
is  made  over  the  prominence,  and  the  skin  and  fascia  are  elevated 
together  and  retracted  downwards.  The  adventitious  bursa 
is  dissected  free  except  at  its  proximal  part,  so  that  it  can  be 
turned  inwards  between  the  first  phalanx  and  the  cut  surface 
of  the  metatarsal.  It  is  stitched  in  this  position,  after  the  head 
has  been  excised. 

Hallux  valgus  may  be  associated  with  a  deformity  of  the 
second  toe,  known  as  "  Hammer  Toe."  The  latter  condition 
may  be  present  alone,  affecting  the  lateral  four  digits  of  each 
foot,  and  it  is  then  not  infrequently  congenital  in  origin.  It 
may,  however,  be  acquired,  independently  of  hallux  valgus, 
by  the  wearing  of  boots  or  shoes  which  are  too  short. 

The  metatarso-phalangeal  and  the  distal  interphalangeal 
joints  are  hyper-extended,  while  the  proximal  interphalangeal 
joint  is  acutely  flexed.  The  prominent  head  of  the  first  phalanx 
may  be  excised  through  a  dorso-lateral  incision.  The  skin  and 
the  dorsal  extensor  expansion,  which  forms  the  dorsal  ligament 
of  the  joint  (cf.  p.  93),  are  divided  and  retracted  to  the  medial 
side.  The  proximal  interphalangeal  joint  is  thus  widely  opened, 
and  after  the  lateral  ligament  has  been  divided  and  the  second 
phalanx  still  further  flexed,  the  head  of  the  first  phalanx  may 
be  dislocated  into  the  wound. 

Hallux  Rigidus,  which  is  not  uncommonly  associated  with 
flat  foot,  is  due  to  collapse  of  the  longitudinal  arch  of  the  foot. 
Under  normal  conditions  the  long  axis  of  the  first  metatarsal  is 
directed  forwards  and  downwards,  whereas  the  long  axis  of  the 


THE  NERVES  OF  THE  LOWER  LIMB  499 

phalanges  is  parallel  to  the  ground.  In  hallux  rigidus  the  base 
of  the  metatarsal  sinks  downwards  so  that  its  long  axis  is  brought 
into  line  with  the  axis  of  the  phalanges.  At  the  same  time  the 
head  of  the  bone  becomes  rotated  upwards  and  the  dorsal  portion 
of  its  articular  cartilage  ceases  to  be  articular.  This  exposed 
area  undergoes  fibrous  change,  and  attempts  at  dorsi-flexion 
cause  severe  pain.  Reflex  spasm  of  the  muscles  occurs  and  the 
toe  is  kept  rigid. 


THE   NERVES   OF  THE   LOWER   LIMB. 

The  Nerves  of  the  Lower  Limb  are  derived  from  the 
lumbar  and  sacral  plexuses  (L.  2 — S.  3).  Plexus  injuries  are 
very  rare,  and  with  the  exception  of  the  common  peroneal  nerve, 
the  nerves  of  the  lower  limb  are  seldom  damaged  by  violence. 

The  Femoral  Nerve  (L.  2,  3,  and  4)  is  sometimes  injured 
in  gun-shot  or  stab  wounds,  or  it  may  be  involved  by  a  psoas 
abscess,  but  the  lesion  is  rarely  complete.  The  quadriceps 
femoris  is  paralysed,  and  the  leg,  therefore,  cannot  be  extended, 
but  it  can  be  brought  forwards  in  walking  "  by  using  the 
adductors,  after  the  leg  has  been  everted  "  (Sherren). 

The  sensory  disturbance  is  most  marked  over  the  distal  two- 
thirds  of  the  leg  and  the  adjoining  part  of  the  foot,  on  their 
medial  aspects,  i.e.  over  the  distribution  of  the  saphenous  nerve. 

The  Sciatic  Nerve  (L.  4,  5,  S.  i,  2,  and  3)  consists  of  two 
portions,  the  tibial  (L.  4,  5,  S.  i,  2,  and  3)  and  the  peroneal 
(L.  4,  5,  S.  i,  2),  which,  although  enclosed  in  a  common  sheath 
in  the  proximal  part  of  the  thigh  and  in  the  buttock,  are 
separable  up  to  their  origins  from  the  plexus.  The  sciatic  nerve 
may  be  injured  by  penetrating  wounds,  dislocations  of  the  hip- 
joint,  or  fractures  of  the  pelvis.  The  lesion  is  usually  incomplete, 
and  in  90  per  cent  of  cases  (Makins)  it  is  referable  to  the  peroneal 
part  of  the  nerve. 

When  the  injury  is  complete,  all  the  muscles  of  the  leg  and 
foot  are  paralysed,  and  if  the  nerve  is  divided  in  the  gluteal 
region,  the  hamstrings  are  also  involved.  Flexion  of  the  leg, 
however,  may  be  carried  out  by  the  gracilis  (obturator  n.)  and 
the  sartorius  (femoral  n.). 

Sensory  disturbances  are  limited  to  the  foot  and  the  lateral 
aspect  of  the  leg. 

32  a 


500 


THE  INFERIOR  EXTREMITY 


The  Common  Peroneal  Nerve  (L.  4,  5,  S.  i  and  2)  may  be 
injured  in  fractures  of  the  neck  of  the  fibula,  in  scythe  wounds 
and  during  forcible  movements  of  the  ankylosed  knee-joint. 

The  muscles  of  the  anterior  and  lateral  compartments  of  the 
leg  are  paralysed  and  the  foot,  therefore,  adopts  the  attitude 
of  talipes  equino-varus  (p.  495). 


L!V 


,  Lumbo-sacral  trunk 

Superior  gluteal  nerve 

Inferior  gluteal  nerve 


To  piriformis I 


To  piriformi 


Nerve  to  quadratus  femoris 
Nerve  to  obturator  internus 


Sciatic  nerv 


Common 
peroneal  nerve 


Sciatic  nerve 

\       Tibial  nerve 

Post.  cut.  N.  of  thigh  (O.T.  small  sciatic) 
Perineal  N.  and  dorsal  N.  of  penis  |  Pudend: 
Inferior  haemorrhoidal  nerve  /  nerve 

'-Perforating  cutaneous  nerve 

Nerves  to  levator  ani 
Coccygeal  branches 

FIG.  148. — Diagram  of  the  Sacral  Plexus. 

When  the  nerve  is  injured,  proximal  to  the  point  of  origin  of 
its  lateral  cutaneous  branch  (p.  446),  alterations  in  sensibility 
are  found  over  the  dorsum  of  the  foot  and  the  lateral  and  anterior 
aspects  of  the  leg,  but,  when  the  injury  occurs  distal  to  that  point, 
the  sensory  disturbance  is  confined  to  the  dorsum  of  the  foot. 

The  Tibial  Nerve  (L.  4  and  5,  S.  i,  2,  and  3)  is  rarely  injured, 
but  when  it  is  completely  divided,  all  the  muscles  of  the  sole  of 
the  foot  and  of  the  posterior  compartment  of  the  leg  are  paralysed. 


THE  NERVES  OF  THE  LOWER  LIMB 


501 


The  foot,  therefore,,  assumes  the  attitude  of  talipes  calcaneo- 
valgus.  Loss  of  sensibility  occurs  in  the  skin  of  the  sole  of  the 
foot. 

The  Obturator  Nerve  (L.  2,  3,  and  4)  may  be  injured  in 
anterior  dislocations  of  the  hip-joint,  in  obturator  hernise,  or 
during  parturition.  The  injury,  however,  is  very  uncommon. 

With  the  exception  of  the  portion  of  the  adductor  magnus 
supplied  by  the  sciatic  nerve  (p.  410),  all  the  adductor  muscles 
are  paralysed,  but  no  sensory  disturbance  is  caused,  as  the 
obturator  nerve  possesses  no  exclusive  area  of  sensory  supply. 

The  Lateral  Cutaneous  Nerve  of  the  Thigh  (L.  2 
and  3)  possesses  an  area  of  exclusive  supply  over  the  proximal 
third  of  the  lateral  aspect  of  the  thigh.  When  the  nerve  is 
divided,  epicritic  and  protopathic  sensibilities  (p.  97)  are  lost 
over  this  area. 

The  following  table  shows  Kocher's  views  with  regard  to 
the  segmental  innervation  of  the  muscles  of  the  lower  limb 
(cf.  p.  105). 


Nerve. 

Muscles. 

L.   2. 

L.3- 

L.4. 
L.  5- 

S.  i. 

S.    2. 

Cremaster. 
Psoas  major,  iliacus,  pectineus,  sartorius,  and    the  ad- 
ductors, brevis,  longus  and  magnus. 
Quadriceps  femoris,  gracilis,  and  (?)  obturator  externus. 
Glutaeus  medius  and  minimus  ;  semimembranosus,  semi- 
tendinosus  and  biceps. 
Glutaeus  maximus  ;    piriformis,   obturator   internus  and 
gemelli,  quadratus  femoris;    muscles  of  anterior  and 
lateral  compartments  of  leg. 
Muscles  of  posterior  compartment  of  leg;    muscles  of 
sole  of  foot. 

32  & 


502      THE  THORAX  AND  VERTEBRAL  COLUMN 


THE   THORAX   AND    VERTEBRAL   COLUMN. 


THE    THORACIC    WALL. 

Surface  Landmarks. — The  upper  border  of  the  manubrium 
sterni,  which  is  on  the  same  horizontal  level  as  the  fibre-cartilage 
between  the  second  and  third  thoracic  vertebrae,  can  be  felt 
in  the  jugular  (supra-sternal)  notch. 

The  junction  between  the  manubrium  and  the  body  of  the 
sternum  is  marked  by  a  transverse  ridge,  which  is  known  as  the 
sternal  angle  (of  Louis).  The  second  costal  cartilage  articulates 
with  the  sternum  at  the  lateral  extremity  of  the  sternal  angle 
and  can  always  be  identified  with  certainty.  As  the  first  costal 
cartilage  is  obscured  by  the  clavicle,  the  sternal  angle  is  a 
valuable  landmark  when  it  is  necessary  to  identify  the  individual 
ribs. 

The  anterior  halves  of  the  second  and  third  ribs  are  almost 
horizontal,  and  the  corresponding  interspaces  are  widest  near 
the  sternum.  The  lower  costal  cartilages  ascend  with  increasing 
degrees  of  obliquity,  and  the  corresponding  interspaces  are 
greatest  at  the  junction  of  the  ribs  with  their  cartilages. 

The  muscular  landmarks  produced  by  the  pectoralis  major 
(p.  2)  and  the  muscles  of  the  back  (p.  239)  have  already  been 
described. 

The  apex-beat  of  the  heart  is  felt  in  the  fifth  intercostal  space, 
3^  inches  from  the  median  plane.  It  is  not  always  visible, 
but  it  can  always  be  felt,  especially  if  it  is  accelerated  and 
strengthened  by  slight  physical  exercise. 

Fracture  of  the  Ribs  may  result  either  from  direct  or 
from  indirect  violence.  In  the  former  case,  the  broken  ends  are 
forced  inwards.  They  may  penetrate  the  pleura  and  wound 
the  lung,  or  they  may  pierce  the  diaphragm  and  injure  the  liver 
or  the  spleen.  Hsemo-thorax,  pneumo-thorax,  or  surgical 
emphysema  may  result. 

When  the  injury  is  due  to  indirect  violence,  the  thorax  being 
compressed  antero-posteriorly,  the  rib  commonly  breaks  just 
in  front  of  its  angle,  and  the  fragments,  which  subsequently 
tend  to  overlap,  are  in  the  first  place  forced  outwards.  On 


THE  THORACIC  WALL  503 

this  account,  there  is  little  danger  of  injury  to  the  deeper 
structures. 

The  Intercostal  Spaces  are  occupied  by  the  internal  and 
external  intercostal  muscles,  with  their  vessels  and  nerves.  The 
fibres  of  the  external  intercostals  pass  downwards  and  medially 
from  the  lower  border  of  the  costal  groove  of  the  rib  above  to 
the  upper  border  of  the  rib  below.  The  fibres  of  the  internal 
intercostals  pass  downwards  and  laterally  from  the  upper 
border  of  the  costal  groove  of  the  rib  above  to  the  upper  border 
of  the  rib  below. 

The  costal  groove  is  placed  on  the  lower  part  of  the  inner 
surface  of  the  rib  and  is  best  marked  posteriorly.  It  lodges 
an  intercostal  vein,  artery,  and  nerve,  which  lie  in  that  order 
from  above  downwards  so  that  the  nerve  is  more  exposed  than 
the  vessels.  On  this  account,  when  a  needle  is  passed  into 
the  chest,  the  instrument  is  kept  close  to  the  upper  border  of 
a  rib. 

Medial  to  the  costo  -  chondral  junctions  the  external 
intercostal  muscle  becomes  a  fibro  -  tendinous  sheet,  which 
is  termed  the  anterior  intercostal  membrane.  The  internal 
intercostal  muscle,  although  extending  to  the  lateral  margin 
of  the  sternum  in  front,  is  deficient  at  the  vertebral  end  of  the 
intercostal  space,  where  it  is  replaced  by  the  posterior  intercostal 
membrane. 

The  lateral  extremities  of  the  costal  cartilages  become 
enlarged  in  rickets  and  form  small  elevations,  which  constitute 
the  condition  known  as  the  "  rickety  rosary." 

The  Internal  Mammary  Artery  descends  at  a  distance  of 
half  an  inch  from  the  side  of  the  sternum.  Posteriorly,  it  rests 
on  the  costal  pleura  and,  in  the  lower  part  of  its  course,  on 
the  slips  of  the  transversus  thoracis  (triangularis  sterni),  which 
pass  obliquely  from  the  posterior  aspect  of  the  sternum  to  the 
upper  costal  cartilages.  Anteriorly,  the  artery  is  in  relation 
to  the  costal  cartilages  and  the  internal  intercostal  muscles, 
and  is  crossed  by  the  intercostal  nerves.  At  the  sixth  inter- 
costal space  the  internal  mammary  artery  ends  by  dividing 
into  the  superior  epigastric  (p.  253),  which  descends  in  the 
sheath  of  the  rectus  abdominis,  and  the  musculo-phrenic,  which 
runs  downwards  and  laterally  along  the  costal  origin  of  the 
diaphragm. 

Ligature  of  the  internal  mammary  vessels  for  stab-wounds 
should  be  carried  out  through  a  transverse  incision  over  the 

32  c 


504      THE  THORAX  AND  VERTEBRAL  COLUMN 

sternal  end  of  the  second  intercostal  space.  The  pectoralis 
major  is  split,  and  the'  anterior  intercostal  membrane  and  the 
internal  intercostal  muscle  are  divided  in  the  line  of  the  incision. 
The  vessels  are  then  exposed,  half  an  inch  from  the  sternum,, 
lying  on  the  parietal  pleura. 

A  few  lymph  glands  are  associated  with  the  internal  mammary 
vessels  at  the  medial  ends  of  the  second  and  third  intercostal 
spaces  (p.  26). 

In  the  operation  of  Paracentesis  Thoracis  an  exploring 
needle  is  introduced  into  the  pleural  sac  through  one  of  the 
intercostal  spaces  overlying  the  dull  area.  In  order  to  avoid 
injuring  the  intercostal  vessels  and  nerve,  the  needle  is  inserted 
close  to  the  upper  border  of  the  rib  which  forms  the  lower 
boundary  of  the  space  selected.  When  the  puncture  is  made 
through  the  lower  part  of  the  thoracic  wall,  the  needle  should 
be  directed  upwards  and  inwards  as  soon  as  it  enters  the  pleural 
sac,  lest  the  diaphragm  be  penetrated.  During  the  operation 
the  skin  over  the  selected  space  is  drawn  upwards  so  that,  when 
the  needle  is  withdrawn,  the  track  of  the  puncture  is  practically 
obliterated. 

In  Empyasma  an  incision  is  made  along  the  eighth  or  ninth 
rib,  with  its  centre  in  the  posterior  axillary  line.  During  the 
operation,  the  patient  lies  on  the  sound  side  with  the  arm  of  the 
other  side  flexed  and  adducted.  In  this  position  the  inferior 
angle  of  the  scapula  is  drawn  forwards  and  upwards,  and  the 
seventh  rib  is  exposed.  Care  must  be  taken  to  make  certain 
that  the  incision  is  not  made  over  the  seventh  rib,  as  the  wound 
would  be  subsequently  obstructed  by  the  scapula  when  the  arm 
resumed  its  normal  position. 

The  skin  and  fasciae  and  the  lower  border  of  the  latissimus 
dorsi,  which  is  exposed  in  the  posterior  part  of  the  incision,  are 
all  divided,  and  the  wound  is  deepened  through  the  serratus 
anterior.  The  rib  is  then  exposed  and  an  incision  is  made 
through  the  periosteum  in  its  long  axis.  A  transverse  cut  is 
made  at  each  extremity  of  this  incision,  and  the  periosteum  is 
then  stripped  off  both  surfaces  of  the  rib.  A  portion  of  the  rib 
can  be  resected  without  injuring  the  intercostal  vessels  and 
nerves.  The  wound  is  then  deepened  through  the  inner  layer 
of  the  periosteum  and  the  costal  pleura.  The  pus  must  not 
be  allowed  to  escape  too  rapidly  as  the  sudden  diminution  of 
pressure  may  lead  to  heart-failure.  A  large  tube  is  fixed  in 
position  and  the  edges  of  the  wound  are  drawn  together. 


THE  THORACIC  CONTENTS  505 

When  it  is  necessary  to  resect  one  of  the  lower  ribs,  the 
position  of  the  lower  limit  of  the  pleural  sac  (p.  509)  and  the 
fact  that  the  costo-diaphragmatic  recess  may  be  obliterated  by 
adhesions  must  be  remembered.  Otherwise  the  diaphragm 
may  be  divided  and  the  peritoneal  cavity  opened. 

The  same  method  of  approach  may  be  employed  when  a  rib 
is  the  site  of  tuberculous  disease.  As  much  of  the  infected  bone 
and  of  the  periosteum  on  the  outer  surface  is  removed  as  may 
be  necessary,  but  the  periosteum  on  the  internal  surface,  after 
being  carefully  scraped,  is  left  otherwise  intact  and  the  skin 
wound  is  then  closed. 

When  the  lung  has  been  collapsed  for  some  time  in  the 
presence  of  a  chronic  empyaema,  extensive  resection  of  ribs 
(Estlander,  Schede,  and  Kocher)  may  be  performed  to  allow 
the  chest  wall  to  fall  in  and  obliterate  the  persistent  cavity. 

A  large  semilunar  incision  is  made  over  the  lateral  aspect  of 
the  chest  so  that  its  lowest  part  corresponds  to  the  bottom  of 
the  cavity.  The  anterior  extremity  of  the  incision  may  extend 
upwards  to  the  lower  border  of  the  pectoralis  major,  and  its 
posterior  extremity  may  ascend  between  the  vertebral  border 
of  the  scapula  and  the  vertebral  spines.  In  the  latter  case,  the 
latissimus  dorsi,  the  trapezius,  and  the  rhomboids  are  all  divided. 
The  U-shaped  flap  thus  marked  out  consists  of  all  the  soft  parts 
down  to  the  ribs.  When  it  is  retracted  upwards,  portions  of 
the  second  to  the  eighth  or  ninth  ribs  may  be  resected  from 
their  angles  to  their  costal  cartilages.  The  periosteum  and  the 
thickened  parietal  pleura  are  also  removed  so  that  the  chest 
wall  may  be  able  to  fall  in  upon  the  collapsed  lung. 

In  certain  cases  the  lung  may  be  decorticated  of  its  thickened 
visceral  pleura  in  the  hope  that  it  may  be  able  to  re-expand. 


THE  THORACIC   CONTENTS. 

The  Pleurae. — Each  lung  is  enclosed  in  a  serous  membrane, 
termed  the  pleural  sac.  The  pleural  membrane  consists  of  a 
visceral  layer,  which  is  closely  adherent  to  the  lung  and  lines 
the  fissures  in  its  substance,  and  a  parietal  layer.  The  two 
pleural  sacs  are  separated  from  one  another  by  the  mediastinal 
space,  which  contains  the  heart,  the  great  vessels,  the  trachea, 
the  oesophagus,  etc.,  and  those  parts  of  the  pleural  membrane 


506      THE  THORAX  AND  VERTEBRAL  COLUMN 


which  form  the  lateral  boundaries  of  the  mediastinum  are 
termed  the  mediastinal  pleura. 

When  the  arrangement  of  the  pleura  is  examined  in  a 
transverse  section  of  the  thorax  at  the  level  of  the  fourth  thoracic 
vertebra,  it  is  seen  that  the  costal  pleura  lines  the  inner 
surfaces  of  the  ribs  and,  anteriorly,  it  passes  medially  behind 
the  sternum  to  the  median  plane.  The  membrane  is  then 
reflected  backwards  over  the  great  vessels  till  it  reaches  the 
vertebral  column. 

If  the  section  is  made  at  a  slightly  lower  level  (Fig.  149),  it 


Costal  part  of  parietal  pleur 

Pleural  cavity  Nv 
Visceral  pleura 


Costal  part  of  parietal  pleura 
Pleural  cavity 
Visceral  pleura 


FIG.  149. — Diagram  of  a  Transverse  Section  through  the  Thorax, 
at  the  Level  of  the  Root  of  the  Lung. 

passes  through  the  root  of  the  lung.  On  passing  backwards 
from  the  sternum,  the  mediastinal  pleura  clothes  the  pericardium 
and  reaches  the  anterior  aspect  of  the  root  of  the  lung,  on  which 
it  is  carried  laterally  to  become  continuous  with  the  visceral 
pleura.  After  covering  the  lung,  the  pleura  is  carried  medially 
on  the  posterior  aspect  of  the  root  and  again  reaches  the 
pericardium,  on  which  it  passes  backwards  to  the  vertebral 
column. 

When  a  frontal  section  is  examined,  it  is  found  that,  when 
the  costal  pleura  is  traced  downwards,  it  extends  for  some 
distance  below  the  lower  border  of  the  lung  and  is  then  reflected 
on  to  the  diaphragm.  In  this  inferior  extremity  of  the  pleural 


THE  THORACIC  CONTENTS 


507 


sac,  which  is  termed  the  phrenico-costal  sinus,  the  costal  and 
diaphragmatic  pleurae  are  in  immediate  contact  with  one  another 
for  a  considerable  distance  during  ordinary  quiet  inspiration. 

The  costal  pleura  becomes  continuous  with  the  mediastinal 
pleura   not   at   one   point    only,   as   in    Fig.    149,   but    along 


\ 


FIG.  150. — Surface  Relations  of  the  Liver,  Stomach,  Lungs,  Heart 

and  Pleural  Sacs. 

Blue  line  —  outline  of  lung.  Dotted  blue  line  =  lines  of  pleural  reflection. 
Fine  black  line  =  heart  and  great  vessels.  Heavy  black  line  =  liver.  Dotted 
black  line  =  stomach. 

a  line  termed  the  costo-mediastinal  line  of  pleural  reflection, 
and  similarly  the  costal  pleura  becomes  continuous  with  the 
diaphragmatic  pleura  along  a  line  which  is  termed  the  costo- 
diaphragmatic  line  of  pleural  reflection.  These  lines  indicate  the 
limits  of  the  pleural  sacs  and  their  relation  to  the  surface  of  the 
body  is  of  great  importance. 

Superiorly,  the  pleura  bulges  upwards  for  about  one  inch 


5o8      THE  THORAX  AND  VERTEBRAL  COLUMN 


above  the  sternal  end  of  the  clavicle  into  the  root  of  the  neck. 
In  this  area  the  apex  of  the  lung  is  in  close  contact  with  the 
parietal  pleura,  which  separates  it  from  the  subclavian  artery 

(p.  142). 

Surface  Relations 
of  the  Lungs  and 
Pleural  Sacs.  —  The 
Cervical  Pleura  can  be 
indicated  on  the  surface 
by  a  curved  line,  with  an 
upward  convexity,  drawn 
from  the  centre  of  the 
sterno-clavicular  joint  to 
the  junction  of  the  sternal 
and  middle  thirds  of  the 
clavicle.  The  summit  of 
the  convexity  should  not 
be  more  than  one  inch 
above  the  clavicle  (Fig. 


The  Costo-Medias- 
tinal  Line  of  Pleural 
Eeflection  is  not  the 
same  on  both  sides  of 
the  body.  On  the  right 
side  it  commences  above 
at  the  sterno-clavicular 
joint  and  passes  down- 
wards and  medially  to 
the  centre  of  the  manu- 
brium  sterni.  From  that 
point  it  descends  vertic- 
ally, in  or  near  the 
median  plane,  to  the 
level  of  the  sixth  costal 
cartilage,  where  it  becomes  continuous  with  the  costo-diaphrag- 
matic  line  of  reflection.  On  the  left  side,  the  line  of  reflection  is 
similar  until  the  level  of  the  fourth  costal  cartilage  is  reached. 
At  that  point  it  deviates  laterally  to  the  left  border  of  the 
sternum  down  which  it  descends  to  the  sixth  chondro-sternal 
articulation,  where  it  becomes  continuous  with  the  costo- 
diaphragmatic  line  of  reflection. 


FIG.  151. — Surface  Relations  of  Right  Lung, 
Pleural  Sac  and  Liver,  from  the  Lateral 
Aspect. 

Blue  line  =  the  lung  and  its  fissures. 

Dotted  blue  line  =  pleural  sac. 

Heavy  black  line  =  liver. 


THE  THORACIC  CONTENTS  509 

In  the  interval  which  is  left  between  the  two  pleural  sacs 
behind  the  lower  part  of  the  left  half  of  the  sternum,  the 
pericardium  comes  into  direct  contact  with  the  anterior  thoracic 
wall  (p.  510). 

The  Costo  -  Diaphragmatic  Line  of  Pleural  Reflection 
indicates  the  lowest  limit  of  the  pleural  sac.  Although  some- 
times a  little  lower  on  the  left  side,  it  may,  for  practical  purposes, 
be  mapped  out  on  the  surface  on  the  two  sides  of  the  body  by 
similar  lines.  It  begins  at  the  lower  end  of  the  costo-mediastinal 
line  and  passes  laterally  and  downwards  behind  the  seventh 
costal  cartilage  and  the  seventh  intercostal  space.  In  the 
lateral  line  (mid-clavicular  or  mammary),  the  costo-diaphragmatic 
line  crosses  the  eighth  rib,  at  its  junction  with  its  cartilage.  It 
continues  to  descend  slightly  as  it  passes  round  the  body,  and 
in  the  mid-axillary  line  it  cuts  the  tenth  rib.  On  the  posterior 
aspect  of  the  trunk  the  line  of  reflection  ascends  slightly  as  it 
passes  towards  the  vertebral  column,  and  crosses  the  eleventh 
and  twelfth  ribs,  the  latter  at  the  point  where  it  is  crossed  by  the 
lateral  border  of  the  sacro-spinalis  (see  also  p.  275).  It  reaches 
the  vertebral  column  at  the  level  of  the  twelfth  thoracic  spine, 
i.e.  nearly  half  an  inch  below  the  head  of  the  twelfth  rib 
(Fig.  84). 

The  Lower  Border  of  the  Lung  lies  at  a  much  higher  level 
than  the  costo-diaphragmatic  line  during  quiet  respiration. 
In  the  lateral  (mammary)  line  the  lower  border  of  the  lung  crosses 
the  seventh  rib  and  lies  about  i£  inches  above  the  lower  limit 
of  the  pleura.  In  the  mid-axillary  line  the  difference  is  most 
marked  and  a  distance  of  three  or  four  inches  separates  the 
lower  border  of  the  lung,  which  is  placed  on  the  eighth  rib,  from 
the  lower  limit  of  the  pleural  sac.  Posteriorly  the  difference 
is  not  so  great,  but  the  phrenico-costal  sinus  extends  usually 
two  inches  below  the  lower  border  of  the  lung,  which  corresponds 
to  the  tenth  thoracic  spine  (Fig.  84).  On  the  right  side  of  the 
body  the  phrenico-costal  sinus  is  related  to  the  liver  and, 
posteriorly,  to  the  upper  pole  of  the  right  kidney  (p.  275).  On 
the  left  side  it  comes  into  relation  successively  with  the  left 
lobe  of  the  liver,  the  stomach,  the  spleen  (p.  320),  and  the  upper 
pole  of  the  left  kidney. 

The  Anterior  Border  of  the  Right  Lung  is  straight  and 
coincides  with  the  costo-diaphragmatic  line  of  pleural  reflection. 
The  Anterior  Border  of  the  Left  Lung  possesses  a  deep  notch 
at  its  lower  end,  which  falls  short  of  the  lateral  margin  of  the 


510      THE  THORAX  AND  VERTEBRAL  COLUMN 

sternum  by  at  least  one  inch.  At  the  sternal  ends  of  the 
fourth  and  fifth  spaces  and  behind  the  sternal  ends  of  the 
fifth  and  sixth  cartilages  of  the  left  side,  the  pericardium  is 
only  separated  from  the  chest  wall  by  a  double  layer  of  pleura. 
Light  percussion  of  this  area,  therefore,  produces  a  dull  note, 
and  the  area  will  be  increased  in  size  when  the  anterior  border 
of  the  left  lung  is  retracted  owing  to  pressure  or  disease  (see 
below). 

The  Heart  and  Pericardium. — The  Pericardium  is  a 
fibro-serous  sac  which  encloses  the  heart  and  the  roots  of  the 
great  vessels.  Under  normal  conditions  its  outline  corresponds 
to  the  outline  of  the  heart,  but,  when  greatly  distended,  it 
becomes  pear-shaped  with  the  blunted  apex  superiorly. 

The  Right  Border  of  the  Heart  is  entirely  formed  by  the 
right  atrium  (auricle).  It  begins  above  at  the  third  right  costal 
cartilage  half  an  inch  lateral  to  the  sternum,  and  descends,  with 
a  slight  convexity  to  the  right,  to  the  sixth  costal  cartilage. 
Its  maximum  distance  from  the  median  plane  is  in  the  fourth 
interspace  and  amounts  to  i|  inches. 

The  Lower  Border  of  the  Heart  extends  from  the  lower 
end  of  the  right  border  to  the  apex-beat  (p.  502).  It  is  formed 
mainly  by  the  right  ventricle,  but  the  left  ventricle  forms  its 
left  extremity. 

The  Left  Border  of  the  Heart  extends  upwards  and 
medially  from  the  apex  to  the  second  left  intercostal  space, 
where  it  lies  at  a  distance  of  half  an  inch  from  the  sternum. 
It  is  gently  convex  upwards  and  to  the  left,  and  corresponds  to 
the  rounded  border  of  the  left  ventricle. 

When  the  heart,  pleurae,  and  lungs  are  marked  in  on  the 
same  chest  (Fig.  150),  it  will  be  found  that  an  irregularly 
triangular  area  of  the  anterior  surface  of  the  heart  is  uncovered 
by  the  left  lung.  This  area  is  termed  the  area  of  superficial 
cardiac  dulness,  and  where  it  extends  beyond  the  sternum  it  is 
covered  by  pleura. 

Effusion  of  fluid  into  the  pericardial  sac  may  greatly 
increase  the  size  of  the  area  of  superficial  cardiac  dulness,  and 
the  lungs  and  pleural  reflections  are  displaced  laterally. 
Curschmann  holds  that  it  is  not  safe  to  perform  paracentesis 
pericardii  at  the  lateral  border  of  the  sternum,  as  the  fluid  tends 
to  collect  posteriorly  and  laterally,  so  that  the  heart  is  thrust 
forwards  against  the  chest-wall.  He  recommends  that  the 
needle  should  be  inserted  in  or  lateral  to  the  lateral  line,  and 


THE  THORACIC  CONTENTS  511 

passed,  in  a  medial  and  backward  direction,,  through  the  anterior 
part  of  the  left  pleural  sac. 

When  the  effusion  is  purulent,  exposure  and  drainage  of  the 
pericardium  is  rendered  necessary.  A  curved  flap  is  turned 
upwards  and  to  the  left,  exposing  the  left  half  of  the  lower  part 
of  the  sternum  and  the  costal  cartilages  of  the  fifth  and  sixth 
ribs.  The  sixth  costal  cartilage  is  carefully  removed  piecemeal 
and  the  internal  mammary  vessels  (p.  503)  are  exposed  lying 
on  the  trans  versus  thoracis  (triangularis  sterni).  When  they 
have  been  ligated,  the  transversus  thoracis  is  divided  and  the 
pericardium  is  exposed  with  a  thin  covering  of  mediastinal  fat. 
If  necessary,  the  fifth  costal  cartilage  and  the  intercostals  may 
be  removed.  The  fat  is  wiped  away,  and  the  left  pleural 
reflection  is  identified  and  displaced  laterally  with  the  ringers. 
The  pericardium  can  then  be  opened  and  drained. 

In  suture  of  the  heart  for  stab-wounds  good  access  is  essential 
and  is  obtained  by  a  modification  of  the  approach  described 
above.  The  incision  is  larger  and  an  extensive  flap  of  the 
chest-wall  may  be  turned  up,  by  dividing  the  third,  fourth,  fifth, 
and  sixth  ribs  after  their  costal  cartilages  have  been  cut  through 
near  the  sternum. 

The  (Esophagus  begins  opposite  the  sixth  cervical  vertebra 
and  descends  through  the  neck,  lying  behind  the  trachea  and 
in  front  of  the  vertebral  column  (p.  139).  In  the  upper  part 
of  the  thorax  it  projects  slightly  beyond  the  left  side  of  the 
trachea  and,  opposite  the  fifth  thoracic  vertebra,  it  is  crossed 
anteriorly  by  the  left  bronchus.  Below  that  point,  the 
oesophagus  lies  behind  the  pericardium  and  in  front  of  the 
vertebral  column,  but  it  curves  forwards  away  from  the  latter 
as  it  leaves  the  thorax.  The  oesophagus  passes  through  the 
diaphragm  opposite  the  tenth  thoracic  vertebra,  and  its 
abdominal  part,  which  is  only  half  an  inch  in  length,  ends  at 
the  cardiac  orifice  of  the  stomach. 

The  oesophagus  is  slightly  constricted  at  its  commencement, 
which  lies  six  inches  from  the  incisor  teeth,  and  again  at  the 
point  where  it  is  crossed  by  the  left  bronchus,  which  lies  four  inches 
lower  down.  It  possesses  a  third  constriction  as  it  passes  through 
the  opening  in  the  diaphragm,  which  is  sixteen  inches  distant 
from  the  incisor  teeth.  (Esophageal  bougies  should  be  graduated 
from  the  distal  extremity  so  that  the  surgeon  may  locate  the 
position  of  an  cesophageal  obstruction.  In  healthy  subjects 
some  obstruction  may  be  encountered  at  the  lower  end  of  the 


512     THE  THORAX  AND  VERTEBRAL  COLUMN 

pharynx,  and  it  is  caused  by  the  bougie  impinging  against  the 
upper  border  of  the  posterior  part  of  the  cricoid  cartilage.  If 
the  patient  swallows,  the  instrument  readily  slips  past  the 
obstruction.  At  a  distance  of  rather  more  than  sixteen  inches 
from  the  incisor  teeth,  the  bougie  enters  the  cardiac  orifice  of 
the  stomach. 

Opposite  the  fourth  thoracic  vertebra,  the  oesophagus  is 
crossed  anteriorly  by  the  aortic  arch  and,  in  cases  of  cesophageal 
obstruction,  the  possibility  that  the  condition  may  be  caused 

Mediastinal  pleura    ... 

-  ~^^'  Mediastmal  pleura 

"8a^|P;>— 
Aortic  arch 

Left  bronchus , 

^ ^          '/,' Vena  azygos 

Left  recurrent  nerve | 

Descending  thoracic  aorta  i^^^^^^j§Thoracic  duct 

Fourth  thoracic  vertebra 

FIG.  152. — Transverse  Section  through  the  Thorax  at  the  Level  of  the 
Fourth  Thoracic  Vertebra. 

by  aneurismal  pressure  must  be  excluded  before  a  bougie  is 
passed. 

Malignant  disease  of  the  oesophagus  commonly  occurs  at 
the  three  places  where  the  tube  is  normally  constricted,  and, 
when  it  is  situated  in  the  upper  thoracic  region,  the  growth  may 
compress  the  left  recurrent  nerve,  which  ascends  in  the  groove 
between  the  left  side  of  the  trachea  and  the  oesophagus  (Fig.  152). 
In  this  situation,  too,  it  may  perforate  the  left  bronchus  and  give 
rise  to  septic  pneumonia. 

When  the  lower  end  of  the  thoracic  part  of  the  oesophagus 
is  the  site  of  new  growth,  the  disease  may  invade  the  right 
pleural  sac  and  cause  an  empysema. 


THE  POSTERIOR  THORACIC  WALL 


THE  POSTERIOR  THORACIC  WALL. 


Costo-Vertebral  Joints. — The  vertebral  end  of  each  typical 
rib  (second-ninth)  articulates  with  the  vertebral  column  by 
two  separate  joints.  The  head  of  the  rib  articulates  with  the 
upper  part  of  the  body  of  the  vertebra  to  which  it  corresponds 
numerically,  with  the  lower  part  of  the  vertebra  above,  and 


Body  of  vertebra 


Posterior  costo-transverse  ligament 

FIG.  153. — Transverse  Section  through  a  Typical  Costo-Vertebral 
Articulation. 


Light  blue  =  articular  cartilage. 
Striped  blue  —  ligaments. 


Green  =  periosteum. 

Red  =  synovial  membrane. 


with  the  fibro-cartilage  between  them.  The  tubercle  of  the  rib 
articulates  with  the  transverse  process  of  the  vertebra  to  which 
it  corresponds  numerically,  and  this  joint  is  strengthened  by  a 
strong  ligament  (the  ligamentum  colli  costce — inter  costo-transverse) 
which  connects  the  posterior  aspect  of  the  neck  of  the  rib  to  the 
anterior  aspect  of  the  transverse  process  (Fig.  153). 

Surgical  Approach  to  the  Posterior  Mediastinum.— 
Tuberculous  disease  or  abscess  affecting  the  thoracic  vertebrae 

33 


514      THE  THORAX  AND  VERTEBRAL  COLUMN 

may  be  attacked  by  the  operation  of  Costo-Transversectomy, 
in  cases  where  conservative  treatment  has  failed  and  where 
paralytic  signs  have  not  improved  with  rest,  or  when  radiograms 
suggest  the  presence  of  sequestra.  As  the  result  of  the  disease, 
a  certain  degree  of  angular  curvature  is  present,  and  the  incision 
begins  near  the  most  prominent  spine.  It  is  carried  laterally 
along  the  rib  below,  which  is  to  be  resected,  and  all  the  soft 
structures  are  divided  until  the  rib  and  the  transverse  process 
with  which  it  articulates  are  exposed.  The  periosteum  is 
elevated  and  the  rib  is  divided  lateral  to  its  tubercle.  The 
transverse  process  is  divided  at  its  medial  end  and  can  be 
disarticulated,  after  the  ligamentum  colli  costae  and  its  other 
connections  have  been  divided.  The  neck  of  the  rib  can  then 


Right  bronchus 


Left  bronchus 
I 


Oesophagus 

'---  Thoracic  duct 
Descending  thoracic  a°rta*^K-^^l-    Vena  azygos 

Pleura 

Fifth  thoracic  vertebra 

FIG.  154.— Diagram  of  a  Transverse  Section  through  the  Upper  Part 
of  the  Posterior  Mediastinum. 

be  cut  through  close  to  the  head.  In  the  last-named  step  care 
must  be  taken  to  leave  the  head  of  the  rib  intact,  lest  the 
sympathetic  trunk,  which  descends  on  the  heads  of  the  ribs,  be 
injured.  The  periosteum  on  the  inner  surface  of  the  rib  is  next 
divided  and  the  pleura,  which  is  now  exposed,  is  retracted. 
A  finger  can  then  be  passed  medially  towards  the  vertebral 
bodies,  and  it  should  be  remembered  that  the  disease  is  most 
advanced  in  the  vertebra  above  the  one  to  which  the  resected 
rib  corresponds  numerically. 

On  the  right  side  of  the  vertebral  column  the  finger  meets 
with  no  obstruction,  but  below  the  level  of  the  third  thoracic 
vertebra  on  the  left  side  the  descending  thoracic  aorta  is 
encountered  (Fig.  154). 

Exposure  of  the  (Esophagus. — In  the  removal  of  a  foreign 
body  from  the  oesophagus  or  a  bronchus,  or  in  excision  of  a 


THE  POSTERIOR  THORACIC  WALL  515 

carcinoma  of  the  oesophagus,  the  mediastinum  must  be  exposed 
more  widely.  Access  is  obtained  by  reflecting  a  large  musculo- 
cutaneous  flap,  about  four  inches  wide,  which  has  its  base  over 
the  vertebral  spines.  When  the  upper  part  of  the  oesophagus 
is  attacked,  the  flap  extends  from  the  first  to  the  seventh 
intercostal  space.  The  medial  portions  of  four  ribs  are  resected 
subperiosteally,  and  after  the  intercostal  vessels  have  been 
ligated  the  periosteum  and  intercostal  muscles  are  carefully 
incised  at  the  medial  part  of  the  wound. 

Owing  to  the  position  of  the  descending  thoracic  aorta 
(Fig.  154)  this  operation  is  usually  performed  on  the  right  side, 
and  it  must  be  remembered  that  the  right  pleural  sac  forms  a 
small  recess  behind  the  right  border  of  the  oesophagus  (Fig.  154). 

Innominate  artery 

Left  innominate  vein  T>  •  u    • 

"/xgjjSti    /^j^^  /^fiO  Kignt  innominate  vein 

&  '  99  m 

Left  common  carotid  a. 

Left  subclavian  a.  I®)  ((j^^^k^T  Trachea 

Left  recurrent  nen^-^        B^  Mediastinal  pleura 

Thoracic  duct  -\jg|||||^  (ESOphagus 
Mediastinal  pleura  — 

--  Body  of  vertebra 

FIG.  155. — Transverse  Section  through  the  Superior  Mediastinum. 

The  pleura  is  stripped  off  the  heads  of  the  ribs,  the  side  of  the 
vertebral  column,  and  the  oesophagus,  and,  if  this  is  done 
carefully,  there  is  little  danger  of  injuring  the  sympathetic 
trunk,  which  descends  on  the  heads  of  the  ribs.  The  oesophagus, 
which  can,  if  necessary,  be  identified  by  passing  an  cesophageal 
bougie,  can  now  be  freed  and  brought  to  the  surface,  a  distance 
of  about  four  inches. 

When  the  oesophagus  is  exposed  on  the  right  side  below  the 
root  of  the  lung,  care  must  be  taken  not  to  injure  the  vagus  nerve, 
which  descends  along  its  lateral  border.  In  this  situation  the 
vena  azygos  and  the  thoracic  duct,  which  lie  behind  the  oesophagus, 
are  not  likely  to  be  injured,  as  they  tend  to  remain  in  contact 
with  the  vertebral  column  when  the  pleura  is  stripped  away 
and  the  oesophagus  is  brought  to  the  surface.  At  the  upper 
border  of  the  root  of  the  right .  lung  the  vena  azygos  turns 


516       THE  THORAX  AND  VERTEBRAL  COLUMN 

forwards,  crossing  the  lateral  aspect  of  the  oesophagus  to  enter 
the  superior  vena  cava,  and,  if  necessary,  it  may  be  ligatured 
in  this  part  of  its  course. 

In  the  upper  part  of  the  thorax  the  oesophagus  lies  slightly 
to  the  left  of  the  median  plane,  and,  as  it  is  situated  above  the 
arch  of  the  aorta,  it  may  be  approached  from  the  left  side.  When 
the  pleura  is  stripped  off  the  vertebral  column  and  retracted, 
the  sympathetic  remains  intact  on  the  heads  of  the  ribs,  but  the 
thoracic  duct  and  the  left  recurrent  nerve  are  exposed  to  injury. 
In  this  part  of  its  course  the  thoracic  duct  is  closely  applied  to 
the  left  border  of  the  oesophagus,  and  it  should  be  identified  and 
separated  before  the  oesophagus  is  freed.  As  the  vagus  crosses 
the  arch  of  the  aorta  it  gives  off  the  left  recurrent  nerve,  which 
ascends  behind  the  vessel,  to  the  left  of  the  trachea  and  in  front 
of  the  left  edge  of  the  oesophagus  (Fig.  155).  The  left  subclavian 
artery  passes  upwards,  backwards,  and  to  the  left  from  the 
aortic  arch,  and  opposite  the  second  thoracic  vertebra  it  is  in 
close  contact  with  the  lateral  border  of  the  oesophagus,  from 
which  it  is  separated  by  the  thoracic  duct.  The  position  of  this 
large  vessel  must  be  kept  in  mind  while  the  oesophagus  is  being 
freed. 


THE  VERTEBRAL  COLUMN  AND  THE 
SPINAL   MEDULLA. 

Ossification  of  the  Vertebrae.  —  Each  typical  vertebra 
possesses  three  primary  centres  of  ossification — one  for  the 
body,  and  one  for  each  half  of  the  verte- 
bral arch.  The  two  halves  of  the 
vertebral  arch  unite  with  each  other 
posteriorly,  and  this  process,  which  begins 
in  the  cervical  region  at  the  end  of  the 
first  year,  extends  very  gradually  to  the 
other  regions,  so  that  it  is  not  completed 
in  the  sacrum  till  between  the  seventh 

„          .          and  tenth  years.     The  vertebral  body  is 
FIG.  156. — Ossification  of  ,    '  . 

a  Vertebra.  separated   from  the  vertebral  arch  on 

each  side  by  a  bar  of  cartilage,  which  is 

termed  the  neuro-central  synchondrosis,  and  it  disappears  about 
the  third  or  fourth  year. 


Centre  for 
body 


THE  VERTEBRAL  COLUMN  517 

In  some  cases  the  neuro-central  synchondrosis  may  persist, 
especially  in   the   lumbar  region.      In  the  interpretation   of 


FIG.   157. — Kyphosis,  produced  by  Tuberculous  Disease  of  Thoracic 
Vertebras.      (From  a  specimen  with  ribs  removed. ) 

radiograms  of  the  vertebral  column,  care  must  be  taken  not 
to  mistake  this  anomaly  for  a  fracture. 

Five  secondary  centres  appear  at  puberty,  and  the  epiphyses 
so  formed  unite  with  the  rest  of  the  bone  at  twenty-five.  They 
are  placed  at  the  extremities  of  the  spine  and  the  transverse 


5i8      THE  THORAX  AND  VERTEBRAL  COLUMN 

processes  and  on  the  superior  and  inferior  aspects  of  the  body. 
The  two  latter  form  ring-like  epiphyses  and  do  not  extend  over 
the  whole  of  the  surfaces  on  which  they  are  situated. 

The  tendency   for    tuberculous  disease   to    attack  growing 
bone  is  well  illustrated  by  the  frequency  of  Pott's  disease  in 


FJG.  158. — Pott's  Disease  in  Thoracic  Region  of  a  Child.     The  abscess 
is  undergoing  calcification  and  absorption. 

childhood  compared  with  its  comparative  rarity  after  puberty. 
The  infection  being  carried  by  the  blood-stream;  the  disease 
begins  as  an  osteo-myelitis  near  the  anterior  surface  of  the  body, 
because  the  nutrient  artery  enters  the  body  posteriorly  and 
breaks  up  into  a  leash  of  small  vessels  about  its  centre.  Owing 
to  the  absence  of  complete  epiphyseal  plates,  it  readily  spreads 
to  the  adjoining  vertebrae. 

If  the  disease  spreads  forwards,  the  anterior  part  of  the 


THE  VERTEBRAL  COLUMN  519 

vertebral  body  is  destroyed  and  collapses,  but  the  posterior 
part  does  not  give  way  to  the  same  extent  owing  to  locking  of 
the  healthy  articular  processes.  As  a  result,  the  part  of  the 
vertebral  column  above  the  disease  is  bent  forwards  on  the 
part  below,  giving  rise  to  angular  curvature  (Fig.  157). 

When  the  disease  spreads  backwards,  the  pus  may  erupt 
through  the  periosteum  and  the  posterior  longitudinal  ligament 
into  the  vertebral  canal,  where  it  lies  outside  the  dura  mater 
and  may  compress  the  spinal  medulla.  If  the  disease  occurs 
before  the  age  of  five,  it  is  prevented  by  the  neuro-central 
synchondroses  from  spreading  postero-laterally  into  the  vertebral 
arch  (Fig.  156). 

The  periosteal  type  of  the  disease  affects  the  anterior  surfaces 
of  the  bodies  of  several  adjoining  vertebrae  and  results  in  a 
gradual  collapse,  which  tends  to  produce  a  gentle  curvature  of 
the  vertebral  column  rather  than  a  sharp  angular  curvature. 

Joints  at  the  Upper  End  of  the  Vertebral  Column.— 
The  Atlas,  or  first  cervical  vertebra,  has  no  body,  and  it  consists 
of  a  short  anterior  arch  and  a  longer  posterior  arch,  connected 
to  one  another  on  each  side  by  the  lateral  mass.  The  superior 
surfaces  of  the  lateral  masses  articulate  with  the  condyles  of  the 
occipital  bone,  and  at  this  joint  only  nodding  movements  of  the 
head  are  possible. 

The  inferior  surfaces  of  the  lateral  masses  articulate  with 
the  superior  articular  facets  of  the  second  cervical  vertebra. 
The  Dens  (Odontoid  Process),  which  represents  the  body  of 
the  atlas,  projects  upwards  from  the  body  of  the  second  cervical 
vertebra.  Its  anterior  surface  articulates  with  the  posterior 
surface  of  the  anterior  arch  of  the  atlas,  and  it  is  held  in  position 
by  the  transverse  ligament,  which  connects  the  two  lateral  masses 
and  is  separated  from  the  posterior  surface  of  the  dens  by  a 
small  bursa  (Fig.  50). 

In  rotatory  movements  of  the  head,  the  atlas,  which  carries 
the  skull  with  it,  moves  on  the  second  cervical  vertebra. 

Tuberculous  disease  not  uncommonly  originates  in  the 
body  of  the  second  cervical  vertebra  or  in  the  dens.  From  the 
latter  situation  it  may  spread  forwards  and  infect  the  articulation 
between  the  dens  and  the  atlas  ;  or,  it  may  spread  backwards 
and  infect  the  bursa  between  the  dens  and  the  transverse 
ligament.  These  joints  are  supplied  by  branches  from  the 
first  and  second  cervical  nerves,  which  also  supply  the  muscles 
which  rotate  the  head.  Irritation  of  the  branches  of  these 


520      THE  THORAX  AND  VERTEBRAL  COLUMN 

nerves  leads  to  reflex  phenomena.  Pain  is  experienced  over 
the  cutaneous  distribution  of  the  second  cervical  nerve  (Fig.  72) 
— the  first  cervical  nerve  has  no  cutaneous  branches — and  the 
head  is  kept  rigid  owing  to  muscular  spasm. 

If  the  transverse  ligament  is  destroyed  or  the  dens  eroded, 
the  head  slips  forwards  and  the  spinal  medulla  (spinal  cord)  is 
crushed.  Death  results  as  the  injury  occurs  above  the  level  of 
the  origin  of  the  phrenic  nerve  (p.  530). 

When  the  body  of  the  third  or  fourth  cervical  vertebra  is 
the  site  of  the  disease,  the  same  rigidity  from  muscular  spasm 
is  present,  and  pain  is  experienced  over  the  cutaneous 
distribution  of  the  third  and  fourth  cervical  nerves.  These 
symptoms  are  due  to  pressure  on  the  nerves  themselves  as  they 
pass  out  from  the  vertebral  canal,  unless  the  joints  between 
the  articular  processes  are  involved,  in  which  case  they  may  be 
entirely  reflex. 

Vertebral  Caries. — In  abscess  formation,  the  pus  may 
escape  to  one  or  other  side  of  the  anterior  longitudinal  ligament, 
which  connects  the  anterior  surfaces  of  the  vertebral  bodies  to 
one  another,  or  it  may  perforate  the  ligament.  It  then  gives 
rise  to  a  retro-pharyngeal  abscess,  which  can  readily  be  recognised 
on  palpation  of  the  posterior  wall  of  the  pharynx  with  the 
finger.  The  abscess  destroys  the  longus  colli  and  comes  to  lie 
behind  the  prevertebral  fascia.  It  may  extend  laterally  (p.  113) 
into  the  floor  of  the  posterior  triangle  (Fig.  36),  and  its  sub- 
sequent course  is  described  on  p.  114. 

The  abscess  may  be  approached  through  an  incision  along 
the  posterior  border  of  the  sterno-mastoid,  which  is  retracted 
forwards  along  with  the  carotid  sheath  (Chiene).  The  anterior 
tubercles  on  the  transverse  processes  are  palpated  and  the 
abscess  is  opened,  slightly  to  their  medial  side,  by  Hilton's 
method  (cf.  evacuation  of  acute  retro-pharyngeal  abscess, 
p.  114). 

When  the  disease  involves  the  lower  cervical  and 
upper  thoracic  vertebrae,  the  affected  part  of  the  vertebral 
column  is  held  rigid  by  muscular  spasm.  Referred  pain  is 
experienced  in  the  upper  limbs  (Fig.  14)  and  its  distribution 
may  help  to  determine  the  precise  site  of  the  disease.  In 
advanced  cases  angular  curvature  may  be  present.  When  an 
abscess  forms,  the  pus  tends  to  track  downwards  behind  the 
anterior  longitudinal  ligament  or  the  prevertebral  fascia  into 
the  mediastinum.  Following  the  course  of  the  dorsal  branch 


THE  VERTEBRAL  COLUMN 


521 


of  an  intercostal  vessel,  it  may  ultimately  point  through  the 
muscles  of  the  back. 

When  the  disease  originates  in  the  mid-thoracic  region, 
muscular  spasm  produces  boarding  and  rigidity  of  the  sacro- 
spinales  and,  sometimes,  the  abdominal  muscles.  Pain  may  be 


Posterior  column  of  spinal  medulla 

Posterior  nerve-root 
Anterior  nerve-root      | 
Spinal  ganglion 
or  rainus  (medial  branch)       ^^^ff^ 


Anterior  column  of  spinal  medulla 


Posterior  rai 

Posterior  ramus  (lateral  brand 

Recurrent  meningeal  branc 

Gray  ramus  coinmimican*  — 

Splanchnic  branch  (white  rainus  ^ 

communi 

Anterior  ram 


Lateral  branch  (poste 
subdivis: 


Lateral  branch 


ateral  branch  (anterior  . 
subdivision) 


^ 


Oiingliated  sympathetic 

trunk 

Efferent  (vaso-motor) 

branch 


Afferent  viscero- 
inhibitory  branch 


FIG.  159. — Scheme  of  the  Distribution  of  a  Typical  Spinal  Nerve. 

experienced  in  the  back,  but  it  is  very  frequently  referred  to  the 
anterior  abdominal  wall,  and  it  may  then  lead  to  errors  in 
diagnosis.  Abscesses  may  point  through  the  muscles  of  the 
back,  or  they  may  follow  the  course  of  an  intercostal  nerve 
and  come  to  the  surface  by  tracking  along  its  lateral  cutaneous 
branch  (Fig.  159). 


522      THE  THORAX  AND  VERTEBRAL  COLUMN 

Abscesses  in  connection  with  the  lower  thoracic  vertebrae 
may  enter  the  posterior  mediastinum  and  gravitate  downwards 
behind  the  medial  lumbo-costal  arch  (internal  arcuate  ligament, 
p.  272).  They  subsequently  descend  under  the  fascial  covering 
of  the  psoas  major  (p.  271). 

When  the  disease  commences  in  the  lumbar  region, 
referred  pain  may  be  experienced  in  the  back,  in  the  lowest 
part  of  the  anterior  abdominal  wall,  in  the  anterior,  medial,  or 
lateral  apects  of  the  thigh,  or  in  the  medial  aspect  of  the  leg 
(Figs.  118  and  124).  Deep  hyperalgesia  may  be  found  in  any  of 
these  areas  and  muscular  spasm  may  also  be  present. 

Abscesses  arising  in  connection  with  the  lumbar  vertebrae 
may  spread  laterally  and  point  in  the  loin  (Fig.  83) ;  or,  they 
may  descend  behind  the  fascial  covering  of  the  psoas  major  and 
follow  the  femoral  nerve  into  the  thigh ;  or,  they  may  follow 
the  glut eal  or  sciatic  nerves  and  enter  the  buttock  (see  also  p.  415). 

Paraplegia  may  come  on  at  any  stage  of  tuberculous  disease 
of  the  vertebral  column,  but  it  occurs  most  frequently  when 
the  upper  thoracic  region  is  involved.  It  is  not  as  a  rule  due  to 
bony  pressure,  for,  although  the  angular  curvature  may  be  so 
marked  that  the  spinal  medulla  is  actually  compressed,  this 
condition  arises  so  gradually  that  it  does  not  lead  to  paralysis. 
Paraplegia  is  usually  caused  by  a  backward  spread  of  the 
disease  into  the  vertebral  canal.  Tuberculous  pachymeningitis, 
or  an  abscess,  or  a  sequestrum  may  compress  the  spinal  medulla 
and  give  rise  to  paralysis  of  the  lower  limbs.  The  signs  of  this 
condition  are  outlined  on  p.  529. 

Examination  of  the  Vertebral  Column.  —  In  suspected 
cases  of  tuberculous  disease,  the  examination  of  the  vertebral 
column  must  be  carried  out  systematically  by  means  of  both 
active  and  passive  movements.  The  active  movements  of 
flexion,  extension,  rotation,  and  lateral  flexion  are  first  examined 
and  any  limitation  is  observed.  The  patient  is  then  placed  face 
downwards  on  the  table  and  passive  movements  are  carried  out 
by  acting  on  the  vertebral  column  through  the  lower  limbs  and 
pelvis.  A  positive  diagnosis  depends,  to  a  large  extent,  on  the 
discovery  of  abnormal  rigidity  due  to  muscular  spasm.  At  an 
early  stage  no  local  pain  can  be  elicited  by  pressure  over  the 
spines,  as  the  disease  originates  in  the  anterior  part  of  the 
vertebral  bodies.  The  sensitiveness  to  deep  pressure  should 
always  be  tested,  as  areas  of  muscular  hyperalgesia  are  frequently 
present  in  the  muscles  supplied  by  the  segment  involved. 


THE  VERTEBRAL  COLUMN  523 

Curvatures  of  the  Vertebral  Column.— In  the  foetus 
the  vertebral  column  shows  two  primary  curves,  both  concave 
forwards.  Of  these,  one  extends  from  the  head  to  the  pelvis 
and  the  other  affects  the  sacral  region.  When  the  child  begins 
to  sit  up  and  elevate  its  head,  a  forward  convexity  appears  in 
the  cervical  region ;  and,  when  the  erect  attitude  is  assumed 
and  the  child  begins  to  walk,  a  forward  convexity  appears  in 
the  lumbar  region  also.  The  development  of  these  secondary 
curves  enables  the  vertebral  column  to  transmit  the  weight  of 
the  trunk  to  the  pelvis  in  such  a  way  that  little  or  no  muscular 
effort  is  required  to  maintain  the  erect  attitude. 

The  amount  of  movement  possible  between  any  two  adjoining 
vertebrae  is  very  small,  but  by  the  summation  of  these  movements 
aided  by  the  compressibility  of  the  intervertebral  fibre-cartilages, 
the  vertebral  column,  as  a  whole,  acquires  a  moderately  extensive 
range  of  movement.  In  flexion  and  extension  of  the  vertebral 
column  the  lumbar  and  cervical  regions  move  more  freely  than 
the  thoracic  region,  but  the  reverse  is  the  case  with  regard  to 
rotation,  except  in  the  case  of  the  joints  between  the  atlas  and 
the  second  cervical  vertebra.  Lateral  flexion  occurs  chiefly  in 
the  lumbar  region. 

In  weakly  children  and  debilitated  adolescents,  the  body 
may  grow  more  rapidly  than  the  muscles  which  support  it. 
These  patients  instinctively  adopt  attitudes  which  relieve  the 
tired  muscles  and  throw  the  strain  on  the  ligaments  of  the 
intervertebral  joints.  The  habitual  adoption  of  such  attitudes 
causes  overstretching  of  the  ligaments  on  which  the  strain  is 
thrown,  and  the  opposing  ligaments  become  shortened.  There 
is,  therefore,  a  tendency  for  the  faulty  attitude  to  be  maintained 
mechanically.  When  the  proper  alignment  of  the  vertebral 
column  is  altered,  the  muscular  balance  is  upset.  One  group  of 
muscles  obtains  a  mechanical  advantage  over  the  corresponding 
antagonistic  group,  which  consequently  becomes  overstretched. 
As  a  result,  abnormal  curves  appear  in  the  vertebral  column. 

Lateral  Curvature,  or  Scoliosis,  occurs  primarily  in  the 
thoracic  region  and  its  convexity  is  usually  directed  to  the 
right  side.  Compensatory  curves,  which  are  convex  in  the 
opposite  direction,  appear  above  and  below  the  primary  curve, 
and  they  serve  to  maintain  the  equilibrium  of  the  body.  The 
lateral  curvature  of  the  thoracic  region  is  not  produced  by  true 
lateral  flexion  of  the  vertebral  column,  as  this  movement  is 
restricted  to  the  lumbar  region.  The  thoracic  vertebrae  become 


524      THE  THORAX  AND  VERTEBRAL  COLUMN 

rotated  and,  at  the  same  time,  extended.  Owing  to  the 
coincident  occurrence  of  rotation,  the  movement  of  extension 
produces  a  lateral  curvature  instead  of  a  diminution  of  the 
normal  forward  concavity.  The  vertebral  spines  lie  in  the 
concavity  of  the  curve  and,  as  they  are  close  to  the  median  plane, 
the  apparent  amount  of  lateral  curvature,  as  estimated  by 
examination  of  the  spines,  is  much  smaller  than  the  actual 
amount. 

In  the  later  stages,  the  unequal  distribution  of  pressure 
hinders  growth  in  what  was  originally  the  posterior  part  of 
the  body,  and  the  vertebral  bodies  become  wedge-shaped. 

The  direction  of  the  ribs  is  necessarily  affected  by  the 
rotation  of  the  thoracic  vertebrae.  On  the  convex  side  of  the 
curve,  the  ribs  produce  a  "  hump  "  on  the  dorsal  aspect  of  the 
body  and  cause  elevation  of  the  scapula  and  shoulder.  On  the 
anterior  aspect  of  the  body  the  ribs  are  thrust  forwards  (i.e.  on 
the  concave  side  of  the  curve). 

The  alteration  in  the  shape  of  the  thorax  causes  a  correspond- 
ing alteration  in  the  shape  and  position  of  the  viscera  which  it 
contains. 

The  condition  of  scoliosis  usually  occurs  in  weak  children 
and  debilitated  adolescents,  but  it  may  be  congenital  or  it  may 
follow  acute  anterior  poliomyelitis  (cf.  p.  494).  It  can  be 
distinguished  from  Pott's  disease  by  the  absence  of  muscular 
rigidity. 

The  backward  curvature  of  Kyphosis,  which  occurs  in 
Pott's  disease  (p.  519),  may  be  caused  by  constitutional  bone 
disease  or  occupational  postures.  It  may  also  occur  in  rickets, 
owing  to  weakness  of  the  muscles  of  the  back. 

The  forward  curvature  of  Lordosis  is  generally  compensatory 
to  flexion  at  the  hip-joint  (p.  435). 

The  Spinal  Medulla  (Spinal  Cord)  begins  at  the 
foramen  magnum,  where  it  is  continuous  with  the  medulla 
oblongata,  and  terminates  at  or  just  below  the  lower  border  of 
the  first  lumbar  vertebra.  In  the  infant  it  is  relatively  longer 
and  extends  to  the  upper  border  of  the  third  lumbar  vertebra. 
The  segments  of  the  spinal  medulla  are  therefore  more  crowded 
together  than  the  corresponding  vertebrae,  and  although  the 
nerve-roots  pass  horizontally  to  the  intervertebral  foramina  in 
the  upper  cervical  region,  their  course  within  the  vertebral 
canal  becomes  longer  and  more  oblique  in  the  thoracic  region, 
while  the  lumbar  and  sacral  nerve-roots  descend  almost  vertically. 


THE  SPINAL  MEDULLA 


525 


Floor  of  fourth  ventricle 
Vertebral  artery 


Transverse  sinus 


Second  cervical  nerve 


Cervical  enlargement 


J    Lower  end  of  spinal 
"  medulla 


FIG.  1 60. —The  Spinal  Medulla  /;/  situ.  The  dura  mater  has  been  partially 
removed  on  the  right  side  and  two  of  the  intercostal  nerves  have  been 
traced  in  a  lateral  direction. 


526      THE  THORAX  AND  VERTEBRAL  COLUMN 

On  transverse  section  (Fig.  161)  it  is  seen  that  the  grey 
matter,  on  each  side,  is  arranged  in  two  columns.  The  anterior 
column  is  broad  and  blunted  and  contains  the  motor  cells  which 
give  origin  to  the  fibres  of  the  anterior  nerve-roots.  The  posterior 
column,  which  is  continuous  in  front  with  the  anterior  column, 
is  somewhat  pointed,  and  near  its  tip  the  posterior  nerve-roots 
enter  the  spinal  medulla. 

The  anterior  nerve-roots,  which  are  purely  motor,  emerge 
from  the  anterior  column  of  grey  matter  in  series.  The  posterior 
nerve-roots,  which  are  entirely  sensory,  enter  the  spinal  medulla 


FIG.  161. — Diagram  of  a  Transverse  Section  through  the  Spinal  Medulla. 
The  anterior  (motor)  and  the  posterior  (sensory)  nerve-roots  ;  their  union 
to  form  a  typical  spinal  nerve  and  their  subsequent  division  into  anterior 
and  posterior  rami  are  also  shown. 

in  series  on  its  postero-lateral  aspect.  Each  posterior  nerve-root 
possesses  a  ganglion,  the  cells  of  which  give  origin  to  peripheral 
and  central  fibres.  In  or  near  the  inter  vertebral  foramina  the 
anterior  and  posterior  nerve-roots  unite  to  form  a  spinal  nerve 
(Fig.  161),  and,  almost  as  soon  as  it  is  formed,  each  spinal  nerve 
breaks  up  into  an  anterior  and  &  posterior  ramus  (primary  division). 
The  rami,  both  anterior  and  posterior,  are  mixed  nerves  ;  their 
distribution  is  dealt  with  in  the  various  regions  of  the  body. 

Membranes. — The  spinal  medulla  is  surrounded  by  three 
membranous  sheaths,  which  are  continuous  with  the  membranes 
of  the  brain  (p.  223).  The  pia  mater  is  closely  applied  to  the 
spinal  medulla  and,  at  its  lower  end,  is  continued  down  as  a  fine 


THE  SPINAL  MEDULLA  527 

thread,  termed  the  filum  terminate.  The  subarachnoid  space  is 
continuous  with  the  subarachnoid  space  in  the  skull,  and  it 
extends  downwards  to  the  second  sacral  vertebra.  Below  that 
point  the  arachnoid  covers  the  filum  terminale.  The  dura 
mater  spinalis  consists  of  a  serous  layer  only,  and  is  not  adherent 
to  the  walls  of  the  vertebral  canal,  to  which  it  is  only  connected 
by  the  spinal  nerves.  The  subdural  space  is  only  continued 
downwards  to  the  second  or  third  sacral  vertebra,  and,  below 
that  level,  the  dura  mater  spinalis  is  closely  applied  to  the  filum 
terminale,  which  eventually  blends  with  the  periosteum  on  the 
back  of  the  coccyx. 

Lumbar  Puncture. — The  lower  part  of  the  sheath  formed  by 
the  arachnoid  and  dura  mater  contains  only  the  lumbar  and 
sacral  nerve-roots  and  the  filum  terminale,  which  form  a  leash, 
termed  the  cauda  equina.  In  lumbar  puncture,  advantage  is 
taken  of  the  absence  of  the  spinal  medulla  from  the  lumbar  part 
of  the  vertebral  canal  to  introduce  an  exploring  needle  into  the 
subarachnoid  space.  The  operation  may  be  performed  in  order 
to  withdraw  some  of  the  cerebro-spinal  fluid  for  examination, 
or  to  inject  drugs  for  the  purpose  of  inducing  anaesthesia. 

The  space  between  adjoining  laminae  is  greatest  in  the  lower 
lumbar  region,  and  on  that  account  either  the  interval  between 
the  third  and  fourth  or  that  between  the  fourth  and  fifth  lumbar 
vertebrae  is  selected.  The  patient  is  placed,  preferably,  in  a 
sitting  posture  with  the  trunk  strongly  flexed,  since  the  interval 
between  the  laminae  is  thus  slightly  increased.  The  interval 
between  the  fourth  and  fifth  lumbar  vertebrae  corresponds  to  the 
line  joining  the  highest  points  on  the  two  iliac  crests,  and  the 
site  of  the  puncture  lies  on  this  line  half  an  inch  from  the  median 
plane.  A  fine  exploring  needle,  fitted  with  a  stilette,  is  thrust 
forwards  and  slightly  upwards  and  medially  through  the  skin, 
fasciae,  and  sacro-spinalis.  After  passing  through  the  muscle 
the  needle  pierces  the  ligamentum  flavum,  which  connects  the 
laminae  ;  the  ligament  can  be  readily  recognised  by  the  resistance 
that  it  causes.  The  needle  then  enters  the  vertebral  canal  and, 
piercing  the  dura  mater  and  arachnoid,  gains  the  subarachnoid 
space,  at  a  distance  of  about  two  inches  from  the  surface.  If  the 
instrument  has  reached  the  subarachnoid  space,  withdrawal  of 
the  stilette  will  be  followed  by  the  escape  of  cerebro-spinal  fluid. 
It  is  apparently  immaterial  whether  the  fluid  withdrawn  is 
obtained  from  the  subdural  or  from  the  subarachnoid  space. 

When  the  operation  is  performed  for  the  purpose  of  inducing 


528      THE  THORAX  AND  VERTEBRAL  COLUMN 

spinal  anaesthesia,,  the  level  of  the  anaesthesia  may  be  roughly 
regulated  by  the  position  of  the  patient  after  the  injection. 
Where  it  is  desired  to  reach  a  high  level,  the  patient  may  be 
placed  flat  upon  the  back,  but  with  the  head  and  neck  flexed  lest 
the  centres  in  the  medulla  oblongata  become  affected. 

Injuries  of  the  Vertebral  Column  and  the  Spinal 


Dens  f— 


Foramen  in  transverse  ._ 
process 


Joint  between  articular 
processes 


Inferior  articular  pro- 

cess of  4th  cerv.  vert. 

Position  of  emerging 

C-  5 

Articular  process  of 
5th  cerv.  vert. 


Pointer  in  interverte- 
bral  foramen 


FIG.  162. — Unilateral  Rotatory  Dislocation  of  the  Fourth  Cervical  Vertebra. 
The  inferior  articular  process  of  the  fourth  cervical  vertebra  has  slipped 
forwards  over  the  superior  articular  process  of  the  fifth.  In  this  position 
it  usually  presses  upon  the  fifth  cervical  nerve  and  causes  pain  which  is 
referred  to  the  areas  supplied  by  its  terminal  branches. 

Medulla. — The  cervical  part  of  the  vertebral  column  most 
frequently  suffers  injury  since  it  normally  possesses  the  greatest 
range  of  movement.  Slight  injuries  of  the  vertebral  column 
may  produce  serious  results  owing  to  the  delicate  structure  of 
the  spinal  medulla. 

Unilateral,    rotatory   luxation  of  an    articular    process 
may  occur  as  the  result  of  a  sudden  twist  or  bend,  and  may  be 


THE  SPINAL  MEDULLA  529 

partial  or  complete.  In  some  cases  the  dislocation  may  be 
reduced  spontaneously  ;  in  others,  the  condition  may  be  mistaken 
for  a  stiff  or  sprained  neck  and  the  correct  diagnosis  may  be  made 
only  after  radiographic  examination.  The  inferior  articular 
process  slips  forwards  over  the  superior  articular  process  of  the 
vertebra  below,  and  it  may  compress  the  spinal  nerve,  giving 
rise  to  referred  pain  over  its  cutaneous  distribution.  This  injury 
usually  occurs  between  the  third  and  fourth,  fourth  and  fifth, 
or  fifth  and  sixth  cervical  vertebrae,  and  it  may  be  accompanied 
by  bruising  of  the  spinal  medulla  and  extravasation  of  blood 
into  or  around  the  spinal  medulla  (Fig.  162).  The  resulting 
sensory  and  motor  changes  depend  on  the  extent  of  the  lesion. 

Bilateral  dislocations  are  always  accompanied  by  serious 
injury  of  the  spinal  medulla,  and,  when  they  affect  any  of  the 
upper  four  cervical  segments,  death  is  instantaneous,  as  the 
diaphragm  (phrenic  nerve,  C.  3,  4,  and  5)  and  the  other  muscles 
of  respiration  are  all  paralysed. 

Fracture  dislocation,  which  is  a  not  uncommon  injury, 
usually  occurs  in  the  lumbar  or  lower  thoracic  region.  The 
upper  vertebra  passes  forwards  and  the  spinal  medulla  is  crushed 
between  its  laminae  and  the  upper  border  of  the  body  of  the 
vertebra  below.  A  complete  transverse  lesion  of  the  spinal 
medulla  generally  results,  but  sometimes  the  injury  is  only 
partial.  It  may,  at  first,  be  impossible  to  determine  whether 
the  lesion  is  complete  or  only  partial,  as  in  the  latter  case  the 
amount  of  paralysis  is  increased  by  the  pressure  of  the  accom- 
panying extravasation  of  blood.  When  the  injury  is  incomplete, 
gradual  improvement  occurs  as  the  extravasated  blood  becomes 
absorbed.  In  these  cases  the  motor  changes  are  usually  more 
extensive  than  the  sensory  changes. 

A  complete  transverse  lesion  of  the  spinal  medulla  is 
accompanied  by  total  sensory  and  motor  paralysis  of  the  regions 
which  are  innervated  by  the  segments  below  the  lesion.  As  the 
upper  neurone  is  involved,  the  paralysed  muscles  are  spastic, 
and  although  they  may  atrophy  from  disuse,  they  do  not  give 
the  reaction  of  degeneration.  In  the  case  of  the  muscles  which 
are  innervated  by  the  actual  segment  destroyed  by  the  injury, 
the  lesion  is  of  the  lower  neurone  type.  Consequently  these 
muscles  rapidly  become  atrophied,  and  the  reaction  of  degenera- 
tion is  present. 

If  the  injury  occurs  above  the  level  of  the  spinal  centres  for  the 
bladder  and  rectum  (L.  i  and  2),  voluntary  control  over  these 

34 


530      THE  THORAX  AND  VERTEBRAL  COLUMN 

viscera  is  lost  and  reflex  evacuations  occur.  If  the  injury  occurs 
at  or  below  the  level  of  these  centres,  the  viscera  are  paralysed 
and  there  is,  at  first,  retention  of  urine,  and,  later,  a  continual 
overflow.  In  many  cases,  however,  these  centres  are  only 
partially  affected. 

A  complete  hemi-lesion  of  the  spinal  medulla  causes  complete 
paralysis  of  the  muscles  of  the  same  side  of  the  body  which  are 
innervated  by  the  segments  below  the  lesion.  Sensory  changes 
also  occur,  but,  as  all  the  fibres  which  convey  painful  and  thermal 
sensations  and  most  of  those  which  convey  tactile  sensations 
cross  the  middle  line  shortly  after  they  enter  the  spinal  medulla, 
these  changes  are  only  found  on  the  opposite  side  of  the  body. 
Muscle  sense  and  joint  sense,  however,  are  conveyed  by  fibres 
which  ascend  on  the  same  side  till  they  reach  the  medulla 
oblongata,  where  they  decussate.  Loss  of  muscle  and  joint 
sense,  therefore,  is  restricted  to  the  paralysed  limb.  A  narrow 
zone  of  anaesthesia  is  present  at  the  upper  limit  of  the  motor 
paralysis.  In  this  situation  the  sensory  fibres  are  involved  as 
they  enter  the  spinal  medulla  and  the  position  of  the  anaesthetic 
strip  is  a  certain  indication  of  the  site  of  the  lesion.  Immediately 
above  the  zone  of  anaesthesia  there  is  usually  a  narrow  zone  of 
hyperaesthesia. 

Complete  destruction  of  the  spinal  medulla  at  the  level  of  the 
fifth  cervical  segment  is  consistent  with  life,  since  the  nerve- 
supply  to  the  diaphragm  (phrenic  nerve,  C.  3,  4,  and  5)  is  not 
at  once  destroyed.  This  lesion  is  accompanied  by  total  paralysis, 
of  the  upper  neurone  type,  of  the  trunk  and  all  the  limbs.  The 
sensory  paralysis  does  not  extend  so  high  on  the  anterior  surface 
as  it  does  on  the  posterior  surface  of  the  body.  Anteriorly,  the 
line  of  anesthesia  corresponds  to  the  second  costal  cartilage,  as 
the  skin  above  that  level  is  supplied  by  C.  3  and  4  (Fig.  72). 
Posteriorly,  the  line  lies  at  a  higher  level,  since  the  posterior 
rami  of  the  third  and  fourth  cervical  nerves  do  not  extend  so 
far  downwards  as  their  anterior  rami  (Fig.  3).  This  condition 
is  usually  followed  by  an  ascending  myelitis,  which  destroys 
the  spinal  centres  of  the  phrenic  nerve,  causing  death  in  a  few 
days. 

When  the  sixth  cervical  segment  is  destroyed,  the  muscles 
supplied  by  C.  5,  being  unopposed,  produce  a  characteristic 
attitude.  The  upper  limbs  are  abducted  and  laterally  rotated 
at  the  shoulder,  the  forearm  is  flexed  and  supinated.  An 
ascending  myelitis  usually  occurs,  and  destruction  of  the  fifth 


THE  SPINAL  MEDULLA 


} ffi-  [(y-Vzr Internal  capsule,  motor  fibres 

O  ij      ^-*^_  ] 


•  Nucleus  of  3rd  nerve 
-Motor  fibres  in  mid-brain 


\-  Nucleus  of  yth  nerve 
.?~^? Motor  fibres  in  pons 


•Nucleus  ot  i2th  nerve 
'Decussation  of  fillet 

Motor  fibres  in  medulla  oblongata 


1  Decussation  of  pyramids 
Fibres  of  muscle  and  joint  sense 
.ascending  in  posterior  column 

j_\_Lateral  cerebro-spinal  tract 
(crossed  pyramidal) 

^Anterior  cerebro-spinal  tract 


"(direct  pyramidal) 


Afferent  fibres  conveying  muscle 
-and  joint  sense 

-Spinal  ganglion 


Fibres  containing  painful  th 
ind  tactile  stimuli 


ermal 


and  tactile  st 

FIG.  163. — Diagrammatic  Representation  of  the  Chief  Motor  and  Sensory 
Tracts  in  the  Central  Nervous  System.  (After  Purves  Stewart.)  The 
black  lines  indicate  the  paths  of  the  sensory  fibres  and  the  dotted  lines 
indicate  the  paths  of  the  motor  fibres. 


532      THE  THORAX  AND  VERTEBRAL  COLUMN 

segment  is  indicated  by  the  collapse  of  the  upper  limbs  upon 
the  trunk. 

In  transverse  lesions  of  the  spinal  medulla  occurring  between 
the  fourth  cervical  and  the  second  thoracic  segments  the  limit 
of  anaesthesia  on  the  anterior  surface  of  the  body  is  placed  at 
the  level  of  the  second  costal  cartilage  (p.  530).  The  distribution 
of  the  areas  of  altered  sensibility  in  the  upper  limbs  gives  an 
indication  of  the  exact  level  at  which  the  spinal  medulla  is 
injured.  When  a  lesion  occurs  below  the  second  segment  in  the 
thoracic  region,  the  upper  limit  of  the  anaesthesia  corresponds  to 
a  horizontal  line  drawn  round  the  trunk  at  the  level  of  the 
terminal  branches  of  the  intercostal  nerve  which  arises  from  the 
injured  segment.  As  the  thoracic  nerve-roots  pass  downwards 
before  they  leave  the  vertebral  canal,  and  as  the  nerves  sub- 
sequently descend  for  some  distance  before  they  terminate 
(p.  240),  the  site  of  the  injury  to  the  vertebral  column  is  placed 
at  a  much  higher  level  than  the  upper  limit  of  the  anaesthesia. 

A  complete  transverse  lesion  of  the  spinal  medulla  in  the  lower 
thoracic  region  is  accompanied  by  total  motor  and  sensory 
paralysis  of  both  lower  limbs.  Although  the  lesion  in  the 
vertebral  column  is  above  the  level  of  the  transpyloric  plane, 
the  muscles  of  the  abdominal  wall,  which  are  supplied  by  the 
seventh  to  twelfth  thoracic  nerves,  are  little  affected,  and  the 
cutaneous  sensibility  is  altered  only  in  the  lowest  part  of  the  wall. 
Reflex  evacuations  of  the  bladder  and  rectum  occur,  as  the  lesion 
is  above  the  level  of  the  spinal  centres  for  these  viscera  (p.  529). 

In  complete  transverse  lesions  above  the  level  of  the  seventh 
thoracic  segment  all  the  muscles  of  the  abdominal  wall  are 
paralysed  and  the  condition  of  meteorism  supervenes  ;  owing 
to  the  absence  of  the  expulsive  force,  gas  accumulates  in  the 
alimentary  canal  and  the  abdomen  becomes  greatly  distended. 

Fracture  dislocation  in  the  lumbar  region  of  the  vertebral 
column  involves  the  cauda  equina.  All  the  nerve-roots  of  the 
cauda  are  rarely  affected,  and  the  alteration  of  sensibility  in  the 
saddle-shaped  area  supplied  by  the  third  sacral  nerves  (Fig.  116) 
is  usually  asymmetrical.  As  the  condition  arises  from  a  root 
injury,  the  area  of  epicritic  loss  is  smaller  than  the  area  of 
protopathic  loss  (p.  97).  In  these  cases  the  bladder  and 
rectum  are  often  affected,  but  the  paralysis  is  rarely  complete. 

Fracture  of  the  Articular  Processes  alone  does  not  necessarily 
give  rise  to  symptoms  of  nerve  pressure. 

Surgical   Approach  to   the  Spinal  Medulla. — It  may  be 


THE  SPINAL  MEDULLA  533 

necessary  to  expose  the  spinal  medulla  in  order  to  remove  the 
cause  of  pressure,  when  it  is  being  compressed,  or  to  divide  the 
posterior  nerve-roots,  in  intractable  neuralgia  (the  "  crises  "  of 
locomotor  ataxia). 

A  vertical  incision  is  made  in  the  median  plane  and  is  carried 
down  to  the  vertebral  spines.  The  muscles  attached  to  the 
spines  and  laminae  are  elevated  on  both  sides,  and  this  step  may 
give  rise  to  severe  haemorrhage.  The  bleeding,  however,  may 
be  controlled  by  packing  tightly  with  gauze  and  forcibly 
retracting  the  muscular  masses  in  a  lateral  direction.  The 
supra-  and  inter-spinous  ligaments  of  the  vertebra  selected  are 
cut  and  the  lamina  on  each  side  is  divided  with  an  osteotome. 
The  instrument  is  applied  with  its  cutting  edge  at  right  angles 
to  the  inferior  border  of  the  lamina.  In  this  way  there  is  no 
danger  of  cutting  into  the  root  of  the  vertebral  arch  (pedicle), 
and,  if  the  instrument  slips  when  the  division  of  the  lamina  is 
completed,  the  spinal  medulla  cannot  be  injured. 

After  both  laminae  have  been  divided,  the  ligamenta  flava 
(p.  527)  are  cut  across,  and  the  vertebral  arch  may  be  removed. 
Additional  laminae  can  then  be  removed  with  bone  forceps. 
Some  loose  fatty  tissue  containing  numerous  small  veins  is 
exposed  on  the  surface  of  the  dura  mater.  The  haemorrhage 
from  these  veins  may  be  so  great  as  to  necessitate  a  two-stage 
operation. 

The  dura  mater  is  incised,  and  as  the  arachnoid  may  be 
injured  at  the  same  time,  cerebro -spinal  fluid  may  escape  in 
company  with  subdural  fluid.  To  prevent  too  great  an  outflow 
the  head-end  of  the  table  should  be  depressed. 

When  the  operation  has  been  completed,  the  cut  edges  of 
the  dura  mater  are  carefully  united  (p.  536)  and  the  thick  muscular 
flaps  are  replaced. 

Development  of  the  Nervous  System  and  the  Vertebral 
Column. — During  the  second  week  of  intra-uterine  life,  a 
longitudinal  furrow,  termed  the  neural  groove,  appears  on  the 
dorsal  aspect  of  the  embryo.  The  walls  and  floor  of  this  groove 
are  formed  by  a  thickening  of  the  surface  ectoderm.  At  a 
slightly  later  stage  the  margins  of  the  groove  unite  and  it 
becomes  converted  into  the  neural  tube,  which  subsequently 
gives  origin  to  the  whole  of  the  nervous  system.  At  first  the 
dorsal  part  of  the  neural  tube  is  continuous  with  the  surface 
ectoderm,  but  the  two  soon  become  separated  by  mesoderm, 
which  grows  in  from  each  side. 

34  a 


534      THE  THORAX  AND  VERTEBRAL  COLUMN 

The  mesoderm  which  surrounds  the  neural  tube  forms  the 
vertebral  column  and  the  membranes  of  the  brain  and  the 
spinal  medulla.  Two  bars  of  cartilage  appear  in  each  segment, 
one  at  each  side  of  the  neural  tube,,  and  grow  backwards  to  form 
the  vertebral  arch.  They  fuse  with  one  another  dorsally  during 
the  fourth  month  and  enclose  the  neural  tube,  surrounded  by 
a  sheath  of  mesoderm;  which  becomes  differentiated  into  the 
dura  mater,  arachnoid,  and  pia  mater. 

The  cartilaginous  bars  may  fail  to  fuse  on  the  dorsal  aspect 
of  the  neural  tube.  This  condition,  which  is  termed  spina 
bifida,  most  commonly  occurs  in  the  lumbo-sacral  region  and 
may  affect  several  consecutive  segments.  It  is  usually 
associated  with  anomalies  of  the  spinal  medulla  and  its 
membranes,  but  it  may  occur  alone — spina  bifida  occulta. 

The  anomalies  associated  with  spina  bifida  are  subdivided 
into  several  varieties,  and  the  precise  nature  of  the  anomaly  can 
rarely  be  determined  until  the  sac  of  the  tumour  which  it  forms 
is  opened. 

1.  In  a  Meningocele  the    spinal    medulla    is    normal    in 
development  and  position,  and  it  possesses  a  complete  covering 
of  pia  mater.    The  arachnoid  and  the  dura  mater  form  a  hernia, 
filled  with  cerebro-spinal  fluid,  which  projects  backwards  through 
the  deficiency  in  the  vertebral  arches  and  forms  a  tumour  under 
the  skin  of  the  back.     Sometimes  the  dura  mater  is  deficient 
dorsally  and  the  sac  of  the  tumour  is  formed  solely  by  the 
arachnoid  (Fig.   164,  a)  ;   at  others,  the  arachnoid  maintains 
its  normal  relationship  to  the  spinal  medulla  and  the  sac  is 
formed  by  the  dura  mater  alone. 

2.  The  Myelo-Meningocele  differs  from  a  meningocele  in 
that  the  spinal  medulla,  though  normally  developed  and  covered 
by  pia  mater,  herniates  backwards  into  the  sac  of  the  tumour. 
Both  the  spinal  medulla  and  the  nerve-roots  arising  from  it  may 
be  adherent  to  the  inner  wall  of  the  sac  (Fig.  164,  b). 

3.  In  a  Myelo-Cystocele  the  central  canal  of  the  spinal 
medulla  is  enlarged  in  a  backward  direction,  and  its  thin  dorsal 
wall,  which  retains  its  primitive  embryonic  structure,  projects 
through  the  deficiency  in  the  vertebral  arch.     The  dura  mater 
is  said  to  be  completely  absent  over  the  dorsal  surface  of  the 
tumour  and  the  arachnoid  is  in  contact  with  the  skin  (Fig.  164,  c). 

4.  In  a  Myelo-Cysto-Meningocele  the  condition  is  similar 
to  (3),  but,  in  addition,  the  subarachnoid  space  is  greatly  dilated 
and  forms  an  arachnoidal  meningocele. 


THE  SPINAL  MEDULLA 


535 


Note. — In    arachnoidal    meningoceles,    whether    simple    or 
complicated  by  myelo-cystoceles,  fine  strands  are  frequently 


FIG.  164. — Diagram  illustrating  some  of  the  Congenital  Anomalies  of  the 
Vertebral  Column  and  Spinal  Medulla. 

a.  Meningocele.  |        d.  Myelo-cysto-meningocele. 

b.  Myelo-meningocele.  e.    Myelocele,  transverse  section. 

c.  Myelo-cystocele.  |       f.    Myelocele,  longitudinal  section. 

The  dotted  line  represents  the  pia  mater,  the  red  line  the  arachnoid,  and  the  heavy 
black  line  the  dura  mater. 

«,  l>,  c  and  d  show  the  un-united  vertebral  arches  on  transverse  section. 

In  e  and  f  the  vertically  shaded  areas  represent  the  skin. 

In  f  the  central  canal  of  the  spinal  medulla  is  seen  opening  on  the  surface  at  the 
upper  and  lower  limits  of  the  myelocele. 

found  in  the  subarachnoid  space,  connecting  the  arachnoid  to 

the  pia  mater.     These  strands  may  be  not  unlike  spinal  nerves. 

5.  A  Myelocele  is  due  to  an  arrest  of  development  at  the 

34  & 


536     THE  THORAX  AND  VERTEBRAL  COLUMN 

time  of  the  closure  of  the  primitive  neural  groove.  In  a  limited 
area  the  edges  of  the  groove  fail  to  unite  and  the  central  canal 
of  the  spinal  medulla  opens  on  the  dorsal  surface  of  the  foetus. 
The  exposed  area,  which  is  elliptical  in  shape  and  brownish  in 
colour  (the  "  area  medullo-vasculosa "  of  Recklinghausen), 
consists  of  a  flattened  zone  of  neuroglia  containing  a  few  nerve- 
cells.  Rudimentary  anterior  and  posterior  nerve -roots  are 
attached  to  the  ventral  surface  of  the  undeveloped  part  of  the 
spinal  medulla.  Complete  paralysis  is  present  on  both  sides  of 
the  body  below  the  level  of  the  anomaly.  As  the  central  canal 
of  the  spinal  medulla  opens  on  the  surface  (Fig.  164,  /), 
septic  infection  rapidly  occurs  and  death  results  shortly  after 
birth.  These  cases  are  therefore  unsuitable  for  treatment. 

In  the  other  varieties  described  the  sac  may  be  exposed  by 
a  longitudinal  incision,  which  divides  to  surround  the  tumour. 
When  the  tumour  is  situated  in  the  sacral  region,  a  transverse 
incision  may  be  employed  in  order  to  keep  the  wound  as  far  as 
possible  from  the  anus.  On  the  dorsal  aspect  of  the  tumour 
the  skin  is  extremely  thin  over  an  area  of  variable  extent,  and 
this  pellicle  is  enclosed  by  the  incision.  The  skin  is  undercut 
on  each  side  and  the  wall  of  the  sac  is  opened.  The  subsequent 
treatment  depends  on  the  precise  nature  of  the  tumour. 

In  simple  meningocele,  part  of  the  sac  is  removed  and  the 
edges  are  carefully  approximated.  In  myelo-meningocele  the 
spinal  medulla  and  nerve-roots  are  freed,  if  adherent  to  the 
inside  of  the  sac,  and  are  then  replaced  within  the  vertebral 
canal.  Part  of  the  sac  is  removed  and  the  wound  is  closed  in 
two  layers — sac  wall  and  skin. 

In  order  to  prevent  leakage  of  the  cerebro-spinal  fluid,  the 
cut  edges  of  the  sac  wall  are  turned  backwards  and  their  inner 
surfaces  are  carefully  stitched  to  one  another.  In  myelo-cysto- 
meningocele,  part  of  the  sac  may  be  ligatured  and  removed,  but, 
in  this  case  also,  great  care  must  be  taken  to  prevent  subsequent 
leakage  of  cerebro-spinal  fluid. 

Similar  deformities  occur  in  connection  with  the  skull  and 
the  membranes  of  the  brain,  but  they  are  much  rarer.  Cranial 
meningocele,  encephalocele,  and  hydr-encephalocele  correspond 
respectively  to  spinal  meningocele,  myelo-meningocele,  and 
myelo-cysto-meningocele.  They  are  usually  found  in  the 
median  plane,  and  their  commonest  site  is  below  the  external 
occipital  protuberance  in  the  occipital  region. 

A  hydr-encephalocele  in  the  occipital  region  contains  the 


THE  SPINAL  MEDULLA  537 

herniated  dorsal  wall  or  roof  of  the  fourth  ventricle.  When  the 
tumour  occurs  in  the  line  of  the  frontal  (coronal)  suture  it 
contains  a  diverticulum  from  the  lateral  ventricle. 

The  sac  of  the  tumour  is  covered  by  skin,  normal  or  thinned, 
and  it  consists  of  arachnoid,  save  in  simple  meningoceles,  where 
the  dura  mater  may  be  present.  The  sac  is  opened  in  order  to 
ascertain  whether  it  contains  any  brain  tissue  (encephalocele  or 
hydr-encephalocele)  or  merely  cerebro-spinal  fluid  (meningocele). 
If  brain  tissue  is  found  and  cannot  be  reduced  within  the  skull, 
it  may  be  ligated  and  removed.  In  suturing  the  cut  edges  of 
the  membranes  care  must  be  exercised  to  prevent  subsequent 
leakage  of  the  cerebro-spinal  fluid. 


INDEX. 


Abdominal  cavity,  276 
wall,  anterior,  237 
arteries  of,  252 
incisions  in,  247 
lymph  vessels  of,  243 
nerves  of,  240,  250 
surface  landmarks  of,  237 
veins  of,  superficial,  243 
posterior,  269 
Abscess,  alveolar,  145,  184 
cerebellar,  227 
ischio-rectal,  373 
of  liver,  308,  309 
of  lung,  283 
mammary,  26 
parotid,  177 
popliteal,  446 
psoas,  270,  272 

spread  of,  272,  273 
retro-cascal,  286 
retro-pharyngeal,  114,  191,  520 
subdural,  216 
of  temporal  lobe,  231 
Adenoids,  190 
Air-cells,  ethmoidal,  194,  201 

mastoid,  214 
embolus,  no 
sinus,  frontal,  194,  200 

maxillary,  194,  195 
Alcock's  canal,  373 
Allantois,  287 

Alveolo-dental  periosteum,  184 
Anal  canal,  369 
anomalies  of,  381 
blood-supply  of,  370 
examination  of,  372 
lymph  vessels  of,  372 
muscular  coat  of,  369 
nerve-supply  of,  371 
Ankle,  anastomosis  round,  482 


Ankle  (contd.) — 

joint.     See  Joint,  ankle 
region,  477 

injuries  in,  485 

spread  of  tuberculous  disease,  482 
surface  landmarks  of,  477 
Anus,  imperforate,  381 
Aorta,  arch  of,  512 

thoracic,  descending,  514 
Appendix,    vermiform.      See    Pro- 
cess, vermiform 
Arachnoid,  225 
Area  medullo-vasculosa,  536 
Arm,  deep  fascia  of,  38 
intermuscular  septa  of,  38 
muscular  landmarks  of,  38 
Artery  or  Arteries — 
of  abdominal  wall,  253 
alveolar,  inferior,  180,  181 
articular,  of  knee.     See  A.,  geni- 

cular 

auricular,  posterior,  219 
axillary,  32 

aneurism  of,  34 
compression  of,  i 
ligature  of,  33 

azygos.     See  A.,  genicular,  middle 
brachial,  42 
branches  of,  43 
ligature  of,  43,  44 
carotid,  common,  116,  119 

ligature  of,  119,  120 
external,  120 

ligature  of,  121 
internal,  225 

centralis  retinas,  208,  209 
cervical,  ascending,  141 

transverse,  126 
ciliary,  208 
circumflex,  humeral,  18,  34,  39 


539 


540 


INDEX 


Artery  or  Arteries  (contd.) — 
circumflex  (contd.) — 

iliac,  deep,  253 

ascending  branch,  249 
superficial,  253,  399 

lateral,  409 

medial,  410 
coeliac,  296 
colic,  left,  340 

middle,  336 

right,  336 
coronary,  of  lips.     See  A.,  labial 

of    stomach.     See  A.,    gastric, 

left 
cremasteric.      See  A.,  spermatic, 

external 

crico-thyreoid,  122 
cystic,  312 

dental.     See  A.,  alveolar 
digital,  86 
dorsales  lingua?,  145 
dorsalis  pedis,  472,  492 

penis,  386 
epigastric,  inferior,  253,  263 

superficial,  253,  399 

superior,  503 

facial.     See    A.,    maxillary,    ex- 
ternal 
femoral,  406 

axial  anastomosis  of,  408 

ligature  of,  407,  408,  412 
frontal,  219 
gastric,  left,  296 

right,  296 

short,  297 

gastro-duodenal,  296 
gastro-epiploic,  296,  297 
genicular,  445 

middle,  463 
gluteal,  inferior,  418 

superior,  416 

ligature  of,  416 
h»morrhoidal,  inferior,  370 

middle,  370 

superior,  370 
hepatic,  296 
ileo-colic,  333 
interosseous,  common,  71 

dorsal,  71 

volar,  71 
intestinal,  324 
labial,  175 

laryngeal,  superior,  121 
lingual,  122,  145 

ligature  of,  122,  145,  188 
of  mammary  gland,  25 


Artery  or  Arteries  (contd.) — 
mammary,  internal,  503 

ligature  of,  503 
maxillary,  external,  122,  147 
in  face,  174,  198 

internal,  180,  181,  182 
meningeal,  middle,  181,  230 

branches  of,  231,  232 

ligature  of,  231 
mesenteric,  inferior,  341 

superior,  323 
musculo-phrenic,  503 
obturator,  411 

abnormal,  405 
occipital,  122,  219 

ramus  descendens,  136 
ophthalmic,  208 
ovarian,  393 
palatine,  193 

palmar  arch.     See  A.,  volar  arch 
pancreatico  -  duodenal,     inferior, 
323 

superior,  296 
perforating,  410 
peroneal,  476 
plantar,  lateral,  491 

medial,  491 
popliteal,  444,  463 

branches  of,  445 

ligature  of,  445 
profunda  brachii,  39,  43 

cervicis,  137 

femoris,  409 
pudendal,     external,     superficial, 

253,  399 
deep,  409 

internal,  378 

pyloric.     See  A.,  gastric,  right 
radial,  72,  92 

recurrent  branch,  43 

wounds  of,  72 
renal,  351 

supernumerary,  352 
sacral,  middle,  370 
scapular,  transverse,  126 
sigmoid,  342 
spermatic,  external,  257 

internal,  257 
splenic,  296 
to  sterno-mastoid,  135 
subclavian,  129,  131,  142 
subscapular,  34 
superficialis  volae,  72 
supra-orbital,  219 
supra-scapular.     See  A.,  scapular, 
transverse 


INDEX 


Artery  or  Arteries — (contd.) 
temporal,  superficial,  219 
thoracic  axis.  See  A.,  thoraco- 

acromial 
lateral,  31 
superior,  33 
thoraco-acromial,  30 
thyreo-cervical  trunk,  143 
thyreoid,  inferior,  142,  143,  167 

ligature  of,  168 

superior,  121,  167 

ligature  of,  168 

thyroid    axis.     See    A.,    thyreo- 
cervical  trunk 
tibial,  anterior,  471 
posterior,  475 

ligature  of,  476 
ulnar,  71 

wounds  of,  72 
ulnar  collateral,  43 
uterine,  394 
vertebral,  140 

ligature  of,  140 
volar  arch,  deep,  92 

superficial,  86 
Ary-epiglottic  fold,  156 
Asterion,  218 
Astragalus.     See  Talus 
Atlas,  519 

anterior  arch  of,  190 
transverse  process  of,  107 
Auditory  apparatus,  209 

tube,  190,  212 
Auricle,  development  of,  210 
Axilla,  28 

walls  of,  28,  31,  32 
Axillary  sheath,  32,  113 

Bennett's  fracture,  80 
Bent  arm,  50 
Bezold's  mastoiditis,  215 
Bile  duct,  314 

exploration  of,  306 

surgical  approach  to,   314,   315, 
316 

termination  of,  316 
Biliary  colic,  312 
Bladder,  urinary,  358 

blood-supply  of,  361 

distention  of,  359 

extroversion  of,  380 

hypertrophy  of,  361 

nerve-supply  of,  362 

referred  pain,  362 

spinal  centres  for,  529 
Blepharo-spasm,  204 


Border  cells,  215 
Brachial  plexus,  37,  95 

branches  of,  96 

injuries  of,  98 

surgical  approach  to,  127 
Brain,  228 

exploration  of,  231 

ventricular  system  of,  225 
Branchial  arches,  148 
arteries  of,  149 

cysts,  151 

fistula,  150 
Broca's  area,  229 
Bryant's  line,  425 
Bulbo-urethral  glands,  384 
Bulla  ethmoidalis,  194 
Burns'  ligament,  402 
Bursa  or  Bursae — 

under    glutaeus    maximus,    415, 
416 

infra-patellar,  449 

round  knee-joint,  448 

popliteus,  449 

pre-patellar,  448 

subacromial,  13 

ulnar,  88 

Caecum,  329 

prolapse  of,  329 

removal  of,  338 
Calcaneus,  478 

fracture  of,  490 

ossification  of,  489 

surgical  approach  to,  488 

tuberculous  disease  of,  488 
Camper,  fascia  of,  240 
Canal,  adductor,  412 

femoral,  402 

inguinal,  253 
Capitate  bone,  80 
Caput  succedaneum,  221 
Carotid  sheath,  114 
incisions  into,  121 
relations  of,  115 

tubercle,  107 
Carpal  ganglion,  91 
Carpus,  ossification  of,  79 

resection  of,  80 
Carrying  angle,  51 
Cartilage  arytenoid,  155 

corniculate,  155 

cricoid,  155 

Meckel's,  149 

semilunar.       See     Joint,     knee, 
menisci  of 

thyreoid,  154 


542 


INDEX 


Cauda  equina,  527 
Cephal-haematoma,  221 
Cerebello-pontine  angle,  235 

tumours  of,  235 
Cerebral  hemisphere,  228 
Cerebro-spinal  fluid,  222 
Cervical  caries,  113,  520 

sinus,  150 
Cervix  uteri,  390 

stenosis  of,  390 
Chemosis,  235 
Choanae,  190 
Cholecystectomy,  312 
Cholecyst-enterostomy,  313 
Chopart's  amputation,  484 
Chordee,  385 
Chorioid,  209 
Circumcision,  386 
Cisterns,  subarachnoid,  225 

cerebello-medullary,  227 
Clavicle,  i,  10 

dislocations  of,  9 

examination  of,  n 

excision  of,  u 

fractures  of,  n 
in  children,  12 

ossification  of,  10 
Clitoris,  397 
Codman's  bursitis,  14 
Colic,  biliary,  312 

renal,  257,  354 
Colics'  fascia,  240 

fracture,  77 
Coloboma  facialis,  192 
Colon,  ascending,  334 
removal  of,  338 

blood-supply  of,  336,  340,  341 

descending,  340 

iliac,  341 

lymph  vessels  of,  338,  340 

pelvic,  341 

removal  of,  343 

transverse,  335 
Colotomy,  inguinal,  248,  343 
Colporrhaphy,  389 
Columns,  rectal,  370 
Compound  palmar  ganglion,  88 
Conchae,  190,  194 
Conjoined    tendon.     See    Falx    in- 

guinalis  aponeurotica 
Conjunctiva,  204 
Conus  elasticus,  155 
Cornea,  208 

ulcer  of,  204 

Costo-coracoid  membrane,  30 
Costo- trans versectomy,  514 


Cowper's    glands.     See    Bulbo- 

urethral  glands 
Coxa  valga,  427 

vara,  427 

Crest,  urethral,  383 
Cretinism,  169 
Cricoid  cartilage,  107 
Cuneiform  tarsectomy,  495 
Cut  throat,  159 
Cystocele,  389 
Cystotomy,  359 

Dactylitis,  tuberculous,  93 
Decompression,  suboccipital,  227 

temporal,  231 
Dens,  519 

tuberculous  disease  of,  519 
Dentigerous  cysts,  184 
Dentition,  184 
Diaphragm,  pelvic,  356 

urogenital,  378 
Diplopia,  207 
Dorsal  subaponeurotic  space,  91 

incision  into,  92 

infection  of,  91 
Drop  wrist,  102 
Duct,  bile,  314 

cystic,  313 

ejaculatory,  367 

hepatic,  common,  314 

naso-lacrimal,  206 

pancreatic,  318 

termination  of,  316 

parotid,  176 

submaxillary,  144 

vitello-intestinal,  287 
Ductus  defer  ens,  257 
Duodeno-jejunal  flexure,  306 
Duodenum,  303 

surface  marking  of,  307 

ulcer  of,  304 

perforation  of,  286 
Dupuytren's  contraction,  83 
Dura  mater,  223 

Ecchymosis,  subconjunctival,  222 

Elbow  joint.     See  Joint,  elbow 

Elbow  region,  44 

bony  landmarks  of,  44 
tuberculous  disease  in,  59 

Eminence,  intercondylar,  459 

Empyaema,  283,  504 

Encephalocele,  536 

Epididymis,  265,  267 
development  of,  267 

Epiglottis,  155,  161 


INDEX 


543 


Epiphora,  198,  205 
Epispadias,  380 
Epistaxis,  221,  222 
Epitympanic  recess,  212 
Ep-oophoron,  394 
Erb-Duchenne  paralysis,  99 
Eustachian    tube.      See    Auditory 

tube 

Exophthalmos,  222 
Extensor  tendons,  insertion  of,  92 

synovial  sheaths  of,  91 
Eye,  203 
Eyeball,  206,  208 

chambers  of,  209 

check  ligaments  of,  206 

suspensory  ligament  of,  206 
Eyelids,  203 

blood-supply  of,  204 

lymph  vessels  of,  204 

Face,  170 

bony  landmarks  of,  170 

carbuncle  of,  175 

development  of,  191 

incisions  in,  178 

naevus  of,  174 

nerves  of,  cutaneous,  172 

oedema  of,  171 

plastic  operations  on,  172 

skin  of,  171 

Facio-hypoglossal  anastomosis,  178 
Falx  cerebri,  223 

inguinalis  aponeurotica,  245 
Fascia,  axillary,  28 

bulbi,  206 

cervical,  deep,  in 

clavi-pectoral,  29 

of  Colles,  376 

cremasteric,  255 

iliaca,  271 

lumbo-dorsal,  269 

pectoral,  28 
exposure  of,  28 

pelvic,  parietal,  355 
visceral,  357 

peri-nephric,  271 

pretracheal,  114 

prevertebral,  in 

of  Scarpa,  240 

spermatic,  external,  255 
internal,  255 

of  thigh,  400 

trans versalis,  252 
Femur,  condyles  of,  443 
fracture  of,  466 

examination  of,  426 


Femur  (contd.) — 
fractures  of,  438,  439 
supra-condylar,  466 
neck  of,  427 
fractures  of,  438 
injuries  of,  427 
surgical  approach  to,  436 
ossification  of,  420,  451 
separation  of  epiphysis,  466 
shaft  of,  fractures  of,  439,  440 
osteo-myelitis  of,  437 
surgical  approach  to,  437 
Fibula,  fracture  of,  477.     See  also 

Pott's  fracture 
ossification  of,  468,  481 
surgical  approach  to,  477 
Filum  terminal e,  527 
Fingers,  congenital  contraction  of, 

83 

development  of,  95 
fibrous  sheaths  of,  83 
incisions  on,  92 
synovial  sheaths  of,  88 
Fistula  in  ano,  374 
Flat-foot,  465,  493 
Flexure,  colic,  left,  339 

resection  of,  340 
right,  335 

resection  of,  338 
Fold,  ary-epiglottic,  156 
patellar  synovial,  452 
Fontanelles,  221 
Foot,  arches  of,  475 
longitudinal,  492 
transverse,  493 
architecture  of,  492 
deformities  of,  494 
gangrene  of,  492 
joints  of,  483 
surface  landmarks  of,  477 
Foramen,  epiploic  (of  Winslow),  279 
Forearm,  bony  landmarks  of,  65 
bones  of,  fracture  of,  68 

surgical  approach  to,  73 
muscular  landmarks  of,  66 
Fossa,  caecal,  330 
cranial,  anterior,  222 

surgical  approach  to,  232 
middle,  222 

surgical  approach  to,  230 
posterior,  222 
contents  of,  235 
surgical  approach  to,  227 
cubital,  45 
duodenal,  307 
ischio-rectal,  373 


544 


INDEX 


Fossa  (contd.) — 

navicularis,  384 

ovalis,  401 

ovarica,  393 

supra- tonsillar,  188 
Frontal  bone,  fracture  of,  200 

sinus,  200 

empyaema  of,  200 
Fron to-nasal  process,  191 

Galea  aponeurotica,  219 
GaU  bladder,  311 

fundus  of,  313 

nerve-supply  of,  312 

referred  pain,  312 

surgical  approach  to,  251 
Ganglion,  otic,  214 

semilunar,  233 
removal  of,  234 
sequelae  of,  235 

spheno-palatine,  191,  194,  233 
Gasserian  ganglion.     See  Ganglion, 

semilunar 
Gastrectomy,  300 
Gastric  ulcer,  283 
Gastro-enterostomy,  anterior,  302 

posterior,  301 

Genito- urinary  organs,  anomalies  of, 
380 

development  of,  379 
Genu  valgum,  463 

operation  for,  438 

varum,  465 
Gerota's  space,  271 
Glabella,  170 
Glaucoma,  209 
Glossitis,  acute,  187 
Glottis,  spasm  of,  161 
Gridiron  incision,  248 
Gubernaculum  testis,  257 
Gyrus,  central,  anterior,  229 
posterior,  229 

Haematemesis,  311 

Haemorrhage,  subconjunctival,  204, 

205,  222 
Haemorrhoids,  external,  371 

internal,  311,  371 
Hallux  rigidus,  498 

valgus,  498 

Hamate  bone,  hook  of,  66 
Hammer  toe,  498 
Hamulus,  pterygoid,  193 
Hand,  bony  landmarks  of,  80 

lymph  vessels  of,  82 
Harelip,  192 


Head,  bony  landmarks  of,  218 
Heart,  510 
apex  beat  of,  502 
area  of  superficial  dulness,  510 
suture  of,  511 
Heister,  value  of,  314 
Hernia,  congenital,  287 
diaphragmatic,  288 
femoral,  403 

strangulated,  405 
surgical  approach  to,  404 
gluteal,  418 
inguinal  direct,  263 
oblique,  259,  261,  263 
in  female,  264 
funicular  type,  259 
interstitial,  260 
old-standing,  263 
pro-peritoneal,  260 
superficial,  261 
vaginal  type,  259 
radical  cure  of,  261 
obturator,  411 
umbilical,  288 
Herpes  Zoster,  240 
Hesselbach,  triangle  of,  263 
Key's  amputation,  484 

ligament,  402 
Hiatus  tendineus,  412 
Highmore,  antrum  of.     See  Maxil- 
lary sinus 
Humerus — 
diastasis  of,  58 
distal  extremity,  51 
ossification  of,  55 
surgical  approach  to,  60 
epicondyle,  medial,  44 
fracture  of,  63 
ossification  of,  56 
fractures  of,  42 

non-union  of,  41 
proximal  extremity  of,  4 
ossification  of,  15 
resection  of,  39 
surgical  approach  to,  39 
shaft  of,  examination  of,  41 
surgical  neck,  fracture  of,  23 
tubercles  of,  3 

greater,  fracture  of,  23 
Hunter's    canal.      See    Canal,    ad- 
ductor 

Hutchinson's  teeth,  184 
Hydatids  of  Morgagni,  267 
Hydr-encephalocele,  536 
Hydrocele,  267 
congenital,  259 


INDEX 


545 


Hydrocele  (contd.) — 

encysted,  of  round  ligament,  264 
of  spermatic  cord,  260 

intermittent,  259 

radical  cure  of,  268 

surgical  approach  to,  262 
Hydrocephalus,  120,  221 

acquired,  227 

congenital,  226 
Hyoid  bone,  107 

development  of,  149 
Hyperacousis,  214 
Hypophysis,  tumours  of,  202,  225 
Hypospadias,  380 
Hypothenar  eminence,  84 
Hysterectomy,  395 

Ileo-pelvic-colostomy,  327,  345 
Ileum,  322 

identification  of,  322,  323 
Incus,  211,  214 
Infra-orbital  foramen,  171 
Inguinal  ring,  abdominal,  253 

subcutaneous,  239,  254 
Intercostal  spaces,  503 
Intestinal  stasis,  325 
Intestine,  small,  322 

development  of,  345 

lymph  vessels  of,  324 

nerves  of,  325 

referred  pain,  325 

stricture  of,  325 

structure  of,  325 
Intussusception,  ileo-caecal,  334 

ileo- colic,  334 
Iridectomy,  209 
Iris,  209 

Jackson's  veils,  329 
Jejunum,  322 

identification  of,  322,  323 
Joint  or  Joints — 

acromio-clavicular,  10 
ankle,  481 

arthrodesis  of,  488 

level  of,  480 

ligaments  of,  481 

sprains  of,  485 

surgical  approach  to,  487 
calcaneo-cuboid,  484 
carpal,  78 
costo- trans  verse,  513 

ligaments  of,  513 
costo- vertebral,  513 
elbow,  51 

aspiration  of,  55 

dislocations  of,  60 


Joint  or  Joints  (contd.) — 

elbow,  dislocations  of  (contd.) — 
complications  of,  62 
reduction  of,  61 
fractures  around,  62 
fractures  into,  51 
ligaments  of,  52,  53 
surgical  approach  to,  64 
synovial  membrane  of,  54 
of  foot,  483 
hip,  419 

aspiration  of,  424 
dislocation  of,  congenital,  428 
pathological,  432 
traumatic,  430,  431 
reduction  of,  431 
examination  of,  426 
excision  of,  434 
function  of,  426 
surgical  approach  to,  432,  434 
tuberculous  disease  of,  421 
attitude  in,  435 
intra-pelvic  spread  of,  424 
interphalangeal,  line  of,  81 
knee,  452 

aspiration  of,  443 
dislocation  of,  468 
drainage  of,  460 
excision  of,  462 
inspection  of,  461 
ligaments  of,  454 
menisci  of,  455 
injuries  of,  456 
surgical  approach  to,  458 
surgical  approach  to,  460 
synovial  membrane  of,  452 
tuberculous  disease,  459 
metacarpo-phalangeal,  line  of,  81 
occipito-atloid,  519 
radio-carpal,  75 
radio-ulnar,  distal,  75 

proximal,  51 
shoulder,  15 

adhesions  in,  17 
aspiration  of,  18 
capsule  of,  15 
dislocations  of,  20 
complications  of,  23 
reduction  of,  22 
ligaments  of,  15 
surgical  approach  to,  19 
synovial  membrane  of,  17 
sterno-clavicular,  6 
dislocations  of,  9 
ligaments  of,  9 
movements  at,  9 

35 


546 


INDEX 


Joint  or  Joints  (contd.) — 
talo-calcanean,  483 
talo-calcaneo-navicular,  484 
temporo-mandibular,  179 

movements  at,  180 
tibio-fibular,  distal,  482 
wrist,  75 

articular  disc  of,  76 

aspiration  of,  76 

level  of,  76 

ligaments  of,  76 

surgical  approach  to,  79 

Kidneys,  349,  350 

calculi  in,  351 

excision  of,  349,  350 

movable,  353 

position  of,  346 

structure  of,  351 

surgical  approach  to,  273 

tuberculous,  350 
Klumpke  paralysis,  98,  100 
Knee-joint.     See  Joint,  knee 
Knee,  region  of,  441 
injuries  in,  466 
landmarks  in,  441 
referred  pain,  406 
Knuckles,  81 
Kyphosis,  524 

Lacertus  fibrosus,  45 
Lacrimal  ducts,  205 

gland,  205 

puncta,  205 

sac,  205 

Lambdoidal  suture,  218 
Laryngeal  prominence,  107 
Laryngismus  stridulus,  161 
Laryngoscopic  examination,  157 
Laryngotomy,  162 

tube,  162 
Larynx,  154 

excision  of,  162 

lymph  vessels  of,  158 

polypi,  158 

upper  opening  of,  156 

ventricle  of,  157 

vestibule  of,  157 
Leg,  fascia  of,  469 

septa,  intermuscular,  469 

surface  landmarks  of,  468 
Lens,  crystalline,  209 
Leucoma,  209 
Ligament  or  Ligaments — 

of  ankle-joint,  481 

annular,  53,  65 
of  wrist.     See  Lig.,  carpal 


Ligament  or  Ligaments  (contd.) — 
broad,  of  uterus,  387 
calcaneo-fibular,  481 
calcaneo-navicular,  plantar,  484, 

492 
carpal,  dorsal,  90 

transverse,  82 
check,  of  eyeball,  206 
of  Cooper,  25 
coraco-acromial,  13 
coraco- clavicular,  10 
of  costo- transverse  joint,  513 
cruciate,  of  ankle,  470 

of  knee,  458 

rupture  of,  459 
deltoid,  481 
of  elbow-joint,  52,  53 
falciform,  277 
flavum,  527 
gastro-splenic,  281 
of  Gimbernat.     See  Lig.,  lacunar 
gleno-humeral,  18 
ilio- femoral,  420 
inguinal,  244 
interclavicular,  9 
of  knee-joint,  454 
laciniate,  471 
lacunar,  244 
lieno-renal,  281 

of  metacarpo-phalangeal  joint,  93 
orbicular.     See  Lig.,   annular 
patella?,  454 
phreni co- colic,  286 
plantar,  484 

of  Poupart.     See  Lig.,  inguinal 
pubo-prostatic,  true,  357 
round,  of  uterus,  391 
sterno-clavicular,  8 
stylo-man  dibular,  116 
suspensory,  of  axilla,  30 

of  eyeball,  206 

of  ovary,  387 
talo-fibular,  481 

of  temporo-mandibular  joint,  180 
teres,  277 
transverse,  of  ankle,  469 

of  atlas,  519 

of  hip,  420 

of  shoulder,  18 
utero-sacral,  391 
of  wrist-joint,  76 
Limb,  lower,  measurements,  424 
Line,  temporal,  superior,  218 
Linea  alba,  238 

incisions  through,  247 
closure  of,  248 


INDEX 


547 


Linea  (contd.) — 
semicircularis,  247 
semilunaris,  239 
Lineae  transversae,  239,  246 
Lingual  dermoids,  152 
Lip,  upper,  development  of,  192 
Lipoma  arborescens,  54,  453 
Lisfranc's  amputation,  484 
Lithotomy,  lateral,  379 
Little's  disease,  232 
Liver,  307 

abscess  of,  308,  309 

drainage  of,  309 
blood-vessels  of,  310 
development  of,  311 
lymph  vessels  of,  244 
Lordosis,  435,  524 
Ludwig's  angina,  145 
Lumbar  puncture,  527 
triangle,  269 
upper,  269 
Lunate  bone,  80 
Lungs,  509 

surface  relations  of,  508 
Lymph  glands — 

auricular,  anterior,  176,  204 

abscess  of,  177 
axillary,  apical,  30,  32,  36 

central,  35 

cervical,  superficial,  no 
deep,  132 

surgical    approach    to,    134, 

141 

of  colon,  338,  340 
epitrochlear,  44 
infra-clavicular,  30 
mastoid,  no,  215 
occipital,  no 
parotid,  176 

abscess  of,  177 
pectoral,  31,  35 
popliteal,  446 
retro-pharyngeal,  114 
of  stomach,  299 
subinguinal,  deep,  400 

superficial,  400 
submaxillary,  146 
examination  of,  143 
removal  of,  147 
submental,  152 

removal  of,  152 
subscapular,  35 
tonsillar,  133 
Lymph  vessels — 

of  abdominal  wall,  243 
of  anal  canal,  372 


Lymph  vessels  (contd.) — 
of  eyelids,  204 
of  hand,  50,  82 
laryngeal,  158 
of  mammary  gland,  26 
of  nasal  pharynx,  190 
of  penis,  387 
of  rectum,  372 
of  spleen,  321 
of  stomach,  298 
of  testis,  257 
of  tongue,  1 86 
of  tonsil,  189 
of  uterus,  394 
of  vagina,  394 

M'Burney's  point,  248 
Main  en  griff e,  103 
Malleolus,  lateral,  477 

medial,  478 
Malleus,  211,  214 
Mammary  gland,  25 

abscess  of,  26 

development  of,  24 

extent  of,  25 

lymph  vessels  of,  26 
Mandible,  angle  of,  171 

condyle  of,  171 

coronoid  process  of,  171 

dislocation  of,  180 

excision  of,  182 

fracture  of,  180 

operations  on,  181 
Mandibular  arch,  148,  191 
Mastoid    antrum.      See    Tympanic 
antrum 

process,  107 

development  of,  210 
Maxilla,  removal  of,  198 
Maxillary  process,  192 

sinus,  195 

empyaema  of,  195 
malignant  tumours  of,  197 
surgical  approach  to,  196 
Meatus,  acoustic,  external,  210 

development  of,  209 

foreign  bodies  in,  211 

nerve-supply  of,  211 
Meckel's  cartilage,  149 

diverticulum,  327 
Mediastinum,  505 

posterior,  approach  to,  513 
Medulla  oblongata,  235 
Membrane,  thyreo-hyoid,  155 

tympanic,  210,  211 
Meningitis,  basal,  225 


548 


INDEX 


Meningocele,  534 
cranial,  536 
treatment  of,  536 
Mental  foramen,  171 
protuberance,  180 
Mesentery,  279,  322 

of  vermiform  process,  331 
Meso- colon,  pelvic,  341 
transverse,  278,  336 
Mesosalpinx,  387 
Mesovarium,  387 
Metacarpal  bones,  81 
fracture  of,  81 
ossification  of,  93 
resection  of,  93 
Metatarsal  bones,  first,  498 

resection  of,  497 
ossification  of,  497 
tuberculous  disease  of,  497 
Motor  area,  229 
Mouth,  development  of,  191 
Muscle  or  Muscles — 

abductor  digiti  quinti,  84 
pollicis  brevis,  84 

longus,  67,  73 
adductor  brevis,  410 
longus,  410 
magnus,  410 
pollicis,  89 
anconaeus,  73 
biceps,  18,  38,  41 

femoris,  441 
brachialis,  41 
brachio-radialis,  66,  73 
branchial,  149 
buccinator,  176 
bulbo-cavernosus,  377 
complexus.     See  M.,  semispinalis 

capitis 

compressor     urethrae.     See     M., 
transversus  perinei,  deep 
constrictor,  of  pharynx,  144,  190 
coraco-brachialis,  38,  41 
cremaster,  255 
crico-thyreoid,  114,  149,  161 
deltoid,  3,  14 

depressor,  of  hyoid  bone,  154 
digastric,  144 
dilatator  pupillae,  125 
ejaculator  urinae.     See  M.,  bulbo- 
cavernosus 
epicranius,  219 
erector    penis.     See    M.,    ischio- 

cavernosus 

extensor  carpi  radial  is  brevis,  66, 
73 


Muscle  or  Muscles  (contd.) — 
extensor  carpi  radialis  (contd.)- 

longus,  66,  73 
ulnaris,  73 

digitorum  brevis,  478 
communis,  67,  73,  92 
longus,  471 
hallucis  longus,  471 
pollicis  brevis,  73 

longus,  68,  73 

of  facial  expression,  149,  178 
flexor  carpi  radialis,  67,  69 

ulnaris,  66,  67,  69 
digiti  quinti  brevis,  84 
digitorum  longus,  475 
profundus,  73,  84 
sublimis,  69,  84 
hallucis  longus,  475 
pollicis  brevis,  84 

longus,  73 
gastrocnemius,  474 
genio-glossus,  148 
genio-hyoid,  148 
glutaeus  maximus,  415 
medius,  416 
minimus,  416 
gracilis,  410 
hyo-glossus,  144,  154 
of  hypothenar  eminence,  84 
iliacus,  271 
infra-spinatus,  15 
intercostal,  503 
interosseous,  of  hand,  90 
ischio-cavernosus,  377 
of  larynx,  150 
latissimus  dorsi,  37 
levator  ani,  356 

glandulaa  thyreoideaa,  167 

development  of,  169 
palpebrae  superioris,  206 
scapulae,  12,  112,  130 
longissimus  capitis,  136 
longus  colli,  112 
lumbrical,  84 
masseter,  181 
of  mastication,  149,  181 
mylo-hyoid,  144 
oblique,  external,  244 
.  inferior,  138 

of  eye,  206 

internal,  244 

superior,  138 

of  eye,  206 

obturator  externus,  410 

internus,  356 
omo-hyoid,  in,  115,  126,    154 


INDEX 


549 


Muscle  or  Muscles  (contd.) — 
opponens  pollicis,  84 

digit!  quinti,  84 
of  orbit,  206 

tenotomy  of,  208 
palmaris  longus,  67 
pectineus,  410 
pectoralis  major,  29 

minor,  29 
peronaeus  brevis,  473 

synovial  sheath  of,  474 

longus,  473,  493 

synovial  sheath  of,  474 
tuberculous  disease  of,  474 

tertius,  471 
piriformis,  474 
platysma,  108 
popliteus,  447 
pronator  quadratus,  73 

teres,  68 

psoas  major,  270 
pterygoid,  external,  181 

internal,  181 

quadratus  lumborum,  270 
quadriceps  femoris,  408 
recto- urethralis,  357,  369 
rectus  abdominis,  246 
sheath  of,  246 

capitis  posterior  major,  138 

inferior,  206 

lateralis,  207 

median's,  207 

superior,  206 
rhomboid  major,  12 

minor,  12 
sartorius,  409 
scalenus  anterior,  112,  130 

medius,  112,  130 

posterior,  130 
semispinalis  capitis,  136 

cervicis,  137 
serratus  anterior,  31 

paralysis  of,  98 
soleus,  469,  474 
splenius,  112,  130 
stapedius,  214 
sterno-hyoid,  154 
sterno-mastoid,  107,  116 
sterno-thyreoid,  154 
stylo-glossus,  148,  154 
subclavius,  37 
supinator,  73 

longus.   See  M.,  brachio-radialis 
supra-spinatus,  14 
tarsal,  inferior,  205 
temporal,  181 


Muscle  or  Muscles  (contd.) — 
tensor  tympani,  214 
veli  palatini,  193 
teres  major,  37 

minor,  15 

of  thenar  eminence,  84 
thyreo-hyoid,  154 
tibialis  anterior,  469,  471,  479 

posterior,  475,  492 
trachelo-mastoid.     See  M.,  longis- 

simus  capitis 

transversus  abdominis,  245 
perinei,  deep,  378 
superficial,  377 
trapezius,  6 
triceps,  38 

surae,  474 
Myelocele,  535 
Myelo-cystocele,  534 
Myelo-cysto-meningocele,  534 
Myelo-meningocele,  534 
Myx  oedema,  169 

Nasal  bone,  fracture  of,  195 

septum,  189 

deviation  of,  194 
Nasion,  170 
Naso-lacrimal  duct,  206 

development  of,  192 
Navicular     bone,      tuberosity     of, 

479 

of  hand,  80 
Nebulas,  209 
Neck,  107 

anterior  median  line,   150 

development  of,  148 

surface  landmarks  of,  107 
Nelaton's  line,  424 
Nephropexy,  273 
Nerve  or  Nerves — 

of  abdominal  wall,  250 

abducent,  207,  225 

accessory,  116,  122,  125,  135 

alveolar,  inferior,  183 
resection  of,  183 
superior,  183 

ansa  hypoglossi,  154 

auricular,  great,  108,  174 

auriculo- temporal,  174,  183 

axillary,  39 
injury  of,  101 

of  Bell.     See  N.,  thoracic,  long 

buccinator,  174,  183 

chorda  tympani,  148 

circumflex.     SeeN.,  axillary 

crural,  anterior.     See  N.,  femoral 


550 


INDEX 


Nerve  or  Nerves  (contd.) — 

cutaneous,  lateral,  399 

injury  of,  501 

medial,  of  forearm,  38 
injury  of,  399 

posterior,  of  thigh,  418 

of  thigh,  418 
of  deep  sensibility,  97 
descendens  hypoglossi,  116 
dorsalis  penis,  387 

scapula?,  12,  130 

injury  of,  97 

of  epicritic  sensibility,  97 
facial,  177,  213 

bruising  of,  178,  217 

distribution  of,  178 

injury  of,  216 

paralysis  of,  214 
femoral,  406 

injury  of,  499 
gluteal,  inferior,  415 

superior,  417 
hypoglossal,  115,  123,  145 

exposure  of,  179 
ilio-inguinal,  400 
infra-orbital,  172 
intercosto-brachial,  32 
interosseous,  dorsal,  73 
injury  of,  101 

volar,  73 
lacrimal,  172 
laryngeal,  external,  161,  168 

internal,  159 

recurrent.     See  N.,  recurrent 

superior,  159 
lingual,  148,  154,  183 

resection  of,  183 
of  lower  limb,  499 
lumbo-inguinal,  399 
mandibular,  182,  234 

injection  into,  183 
maxillary,  233 

injection  into,  233 

inferior.     See  N.,  mandibular 
median,  37,  72 

in  hand,  86 

injury  of,  104,  105 
mental,  174 
musculo-cutaneous,  37,  42 

injury  of,  102 

of  leg.     See  N.,  peroneal,  super- 
ficial 

musculo- spiral.     See  N.,  radial 
to  mylo-hyoid,  144,  183 
naso-ciliary,  172 
obturator,  400,  411 


Nerve  or  Nerves  (contd.) — 
obturator  (contd.) — 

injury  of,  501 
occipital,  greater,  138 

lesser,  108 

oculo-motor,  207,  225 
olfactory,  194 
ophthalmic,  225,  233 
optic,  209 

perineal,  superficial,  377 
peroneal,  common,  446,  469 
injury  of,  500 

deep,  472 

superficial,  472 
of  pharyngeal  plexus,  190 
phrenic,  112,  115,  312 
plantar,  lateral,  491 

medial,  491 

popliteal,   external.     See  N., 
peroneal,  common 

internal.     See  N.,  tibial 
of  protopathic  sensibility,  97 
pudendal,  374 
radial,  38,  39 

compression  of,  41 

exposure  of,  41 

injury  of,  101 

superficial  branch  of,  71 
injury  of,  101 

surface  marking  of,  40 

termination  of,  41 
ramus  communicans,  grey,   125 

white,  125 
recurrent,  162,  168 

left,  516 
to  rhomboids.     See  N.,   dorsalis 

scapulas 
roots,  526 
saphenous,  406 
of  scalp,  219 
sciatic,  418,  441 

injury  of,  499 

small.      See    N.,    cutaneous, 

posterior,  of  thigh 
spermatic,  external,  257 
spinal,  526 

rami  of,  526 
of  stomach,  298 
subscapular,  lower,  35 
superficial,  of  arm,  45 

of  face,  172 

of  forearm,  45 

of  neck,  108 

of  palm,  82 

of  shoulder  region,  4 

of  thigh,  399 


INDEX 


Nerve  or  Nerves  (contd.) — 
supra-orbital,  172 
supra-scapular,  127 

injury  of,  98 
supra- trochlear,  172 
suralis,  473 
sympathetic  trunk,  124 

injury  of,  120 
thoracic,  long,  131 

injury  of,  97 
thoraco-dorsal,  35 
tibial,  445,  476 

anterior.      See    N.,     peroneal, 

superficial 
injury  of,  500 
trigeminal,  233 

paralysis  of,  204 
trochlear,  207,  225 
ulnar,  38,  69 

dorsal  cutaneous  branch,  71 

in  hand,  85 

injury  of,  at  elbow,  104 

at  wrist,  103 
vagus,  116 
Nervous   system,    development   of, 

533 

Neural  groove,  533 
Neuralgia,  facial,  183 
Nose,  194 

development  of,  191 
meatus,  inferior,  194 
middle,  194 
superior,  194 
nerves  of,  194 
Nuck,  canal  of,  264 

(Edema  glottidis,  157 
CEsophageal  bougie,  511 

diver  ticulum,  139 
(Esophagotomy,  139 
(Esophagus,  in  neck,  139 

in  thorax,  511 
exposure  of,  514 

malignant  disease  of,  512 
Olecranon,  44 

fracture  of,  6r,  63 

resection  of,  65 
Olfactory  pits,  191 
Omental  bursa,  280 

development  of,  303 
Omentum,  lesser,  279 

greater,  279 
Orbit,  206 

fracture  into,  222 
Os  calcis.  See  Calcaneus 

incisivum,  192,  193 


Os  trigonum,  489 
Otoscopic  examination,  211 
Ovary,  392 
cysts  of,  393 

Palate,  cleft,  192 

formation  of,  192 
Palm,  central  part  of,  84 

fascia  of,  deep,  82 
superficial,  81 

fascial  spaces  of,  90 

incisions  into,  86 

muscles  of,  deep,  89 
Palmar  aponeurosis,  82 

space,  middle,  90 
incisions  into,  90 
infection  of,  90 
Pancreas,  317 

blood-supply  of,  318,  319 

cysts  of,  318 

development  of,  319 

ducts  of,  318 
Pancreatitis,  312,  316 
Pan-ophthalmitis,  204 
Papilla,  duodenal,  315 
Paracentesis  pericardii,  510 

thoracis,  504 

tympani,  211 
Paracolic  gutter,  left,  286 

right,  285 
Paradidymis,  267 
Paralysis,  Erb-Duchenne,  99 

Klumpke,  100 
Paraphimosis,  385,  386 
Parathyreoid  glands,  169 
Parietal  tuberosity,  218 
Parotid  gland,  175 
abscess  of,  177 
removal  of,  177 
tumours  of,  177 

duct,  176 

calculi  in,  176 
Patella,  dislocation  of,  467 

floating,  442 

fracture  of,  466 
wiring  of,  467 

ossification  of,  452 
Pelvis  minor,  355 

drainage  of,  286 

fractures  of,  355 

infection  of,  286 
Pelvis,  female,  387 
Penis,  385 

blood-supply  of,  387 

nerve-supply  of,  387 

root  of,  376 


552 


INDEX 


Pericardium,  510 
drainage  of,  511 
effusion  in,  510 
paracentesis  of,  510 
surface  relations  of,  509 
Pericolitis,  329 
Perineum,  373 
female,  396 

laceration  of,  389 
Peritoneal  cavity,  277 
drainage  of,  282 
fossae,  307,  330,  341 
infra-colic  compartment,  283 
supra-colic  compartment,  282 
Peritoneum,  277 

pelvic,  357,  3§7 
Pes  cavus,  491 

Petit,  triangle  of,  lumbar,  269 
Petro-squamous  suture,  212,  215 
Phalanges,  of  hand,  93 
necrosis  of,  82 
ossification,  93 
resection  of,  93 
of  toes,  497 
Pharyngeal  recess,  190 
Pharyngotomy,  subhyoid,  159 
Pharynx,  189 
laryngeal,  191 
nasal,  189 

lymph  vessels  of,  190 
oral,  191 
Phimosis,  385 
Pia  mater,  225 
Pisiform  bone,  66 
Plane,  intertubercular,  239 
lateral,  239 
subcostal,  239 
transpyloric,  240 
Plantar  aponeurosis,  491 
Pleura,  505 

lines  of  reflection,  507 
surface  relations  of,  508 
Plexus,  brachial,  37,  95 
cords  of,  95 

injuries  to,  100 
exposure  of,  127 
lesions  of,  97,  98 
chorioid,  226 
coeliac,  312 

venous,  haemorrhoidal,  370 
pampiniform,  257 
pterygoid,  225 
pudendal,  365 
Plica  sublingualis,  186 
Polydactylism,  95 
Pons,  235 


Popliteal  fossa,  44 
Porta  hepatis,  310 
Portal  obstruction,  310 
Pott's  disease,  518 

fracture,  486 
Pouch,  perineal,  deep,  378 

superficial,  376 
Pre-auricular  point,  171 
Premaxilla.     See  Os  incisivum 
Prepuce,  385 
Process,  coracoid,  2 
fracture  of,  13 
mastoid,  107,  210 
odontoid.     See  Dens 
trochlear,  478 
vermiform,  330 
abscess  of,  333 
position  of,  331 
surgical  approach  to,  248 
Processus  vaginalis,  258 
Prostate,  364 

hypertrophy  of,  365 

effects  of,  366 
Prostatectomy,  perineal,  379 

supra-pubic,  366 
Protuberance,   occipital,   external, 

218 

Pterion,  229 

Pterygo-mandibular  raphe,  171 
Ptosis,  207 
Pylorectomy,  300 
Pylorus,  290 
recognition  of,  294 

Quadrilateral  space,  39 

Radius,  fractures  of,  68,  69,  77 

head  of,  45 

ossification  of,  58 
subluxation  of,  62 

neck,  fracture  of,  63 

ossification  of,  58,  77 

resection  of,  75 

styloid  process  of,  66 

surgical  approach  to,  73 
Ranula,  148 
Recess,  hepato-renal,  283 

intersigmoid,  341 
Recessus,  piriformis,  156 

spheno-ethmoidalis,  194 
Rectocele,  389 
Rectum,  367 

anomalies  of,  381 

blood-supply  of,  370 

examination  of,  372 

excision  of,  381 


INDEX 


553 


Rectum  (contd.) — 

lymph  vessels  of,  372 

nerve-supply  of,  371 

spinal  centres  for,  529 

structure  of,  369 
Referred  pain,  240 
Reflex,  cremasteric,  269 

viscero-motor,  251 

viscero-sensory,  242 
Region,  gluteal,  413 

inguinal,  253 
Retinacula,  peroneal,  471 
Retinal  haemorrhage,  235 
Retropubic  pad  of  fat,  359 
Ribs,  cervical,  128 

nervous  symptoms  of,  100 
removal  of,  129 

fractures  of,  502 

resection  of,  505 
Rickety  rosary,  503 
Rima  glottidis,  157 
Ring,  femoral,  403 

abdominal  inguinal,  253 

subcutaneous  inguinal,  254 
Rolando,    fissure    of.     See    Sulcus, 

central 
Roots,  nerve,  526 

Saphenous     opening.       See    Fossa 

ovalis 

Soalene  tubercle,  130,  132 
Scalp,  218 

blood-supply  of,  218 

cysts  of,  218 

nerves  of,  219 

skin  of,  218 

subaponeurotic  space  of,  219 

venous  return  from,  219 

wounds  of,  219 
Scapula,  anastomosis  round,  33 

excision  of,  13 

fracture  of,  13 

ossification  of,  12 

spine  of,  2 

winging  of,  98 
Scarpa,  fascia  of,  240 

triangle  of.     See  Trigone,  femoral 
Schlatter's  disease,  468 
Sclera,  208 
Scoliosis,  523 

Scrotum,  development  of,  380 
Seminal  vesicles,  367 
Septum  femorale,  402 
Sheath,  axillary,  32,  113 

carotid,  114 

incisions  into,  121 


Sheath  (contd.)— 

carotid,  relations  of,  115 

femoral,  402 

palmar,  common,  87 
incisions  into,  88 
pus  in,  88 
Shoulder,  congenital  elevation  of,  24 

region,  nerves  of,  4 
referred  pain  in,  6 
tuberculous  disease  in,  18 
Sinus,  cavernous,  225 

thrombosis  of,  208,  225,  235 

epididymidis,  265 

lateral.     See  Sinus,  transverse 

occipital,  225 

pocularis.     See  Utricle,  prostatic 

sagittal,  inferior,  223 
superior,  223 

straight,  223 

transverse,  214,  216,  224 

venosus  sclerae,  208,  209 
Skull,  development  of,  221 

fracture  of,  204,  222,  225 
Smith's  fracture,  77 
Snapping  hip,  415 
Spermatic  cord,  255 

arterial  supply  of,  257 

coverings  of,  255 

examination  of,  268 

exposure  of,  254 

hydrocele  of,  encysted,  260 
Sphenoidal  sinus,  201 

empyaema  of,  202 
Spina  bifida,  534 
occulta,  534 
Spinal  medulla,  524 

hemi-lesions  of,  530 

injuries  of,  528 

membranes  of,  526 

path  of  sensory  fibres  in,  530 

structure  of,  526 

surgical  approach  to,  532 

transverse  lesion,  complete,  125, 

529,  530,  532 
Spine,  tibial.     See  Eminence,  inter- 

condylar 
Spleen,  319 

enlargement  of,  321 

lymph  vessels  of,  321 

puncture  of,  321 
Splenectomy,  321 
Stapes,  214,  216 
Sternal  angle,  502 
Stomach,  289 

arteries  of,  296 

development  of,  303 


554 


INDEX 


Stomach  (contd.) — 

examination  of,  294,  296 
radiographic,  294 

fundus  of,  289 

lymph  glands  of,  299 
vessels  of,  298 

malignant  disease  of,  300 

nerves  of,  298 

position  of,  290 

pylorus  of,  290 

referred  pain,  298 

structure  of,  294 

surgical  approach  to,  296 

ulcer  of,  301 

perforation  of,  283,  286 

veins  of,  298 
Stomodoeum,  191 
Strabismus,  convergent,  208 

divergent,  207 
Stye,  203 

Sublingual  gland,  148,  154 
Submaxillary  region,  143 
inflammation  in,  145 

duct,  1 86 

salivary  gland,  144 
Subphrenic,  area,  283 
Sulcus,  central,  228 

surface  marking  of,  229 

lateral,  229 

Supra-hyoid  region,  152 
Supra-orbital  notch,  170 
Supra-sternal  space,  in 
Surgical  emphysema,  195,  200, 

201 

Sustentaculum  tali,  479,  488,  491 
Sylvian  point,  229 
Sylvius,     fissure    of.     See    Sulcus, 

lateral 
Sympathetic  trunk,  124 

in  thorax,  514,  515 
Syndactylism,  95 

Talipes,  494 

acquired,  494 

nerve- anastomosis  in,  496 
tendon      transplantation      in, 
496 

calcaneo-valgus,  494 

calcaneo-varus,  494 

calcaneus,  494 

congenital,  494 
tenotomy  in,  496 

equino-valgus,  494 

equino-varus,  495 

equinus,  494 

valgus,  495 


Talipes  (contd.)— 

varus,  495 

Talma- Morison  operation,  311 
Talus,  480 

dislocation  of,  486 

excision  of,  487 

ossification  of,  489 
Tarsal  glands,  204 
Tarsi,  203 
Tarsus,  fractures  of,  489 

ossifi cation  of,  489 
Teeth,  eruption  of,  184 
Tegmen  tympani,  212 
Temporal  bone,  210 

tuberculous  disease  of,  215 
Tendo    Achillis.      See    Tendo    cal- 
caneus 

calcaneus,  474 

lengthening  of,  475 
rupture  of,  475 
Tenon,    capsule    of.       See    Fascia 

bulbi 

Tentorium  cerebelli,  223 
Testis,  265 

coverings  of,  255 

descent  of,  257 

anomalies  of,  258,  265 

development  of,  267 

examination  of,  268 

excision  of,  266 

gubernaculum,  257 

inversion  of,  267 

lymph  vessels  of,  257 

mediastinum,  266 

processus  vaginalis,  258 

undescended,  265 
Thenar  eminence,  84 

space,  90 

incisions  into,  90 
infection  of,  90 
Thigh,  superficial  vessels,  398 

surface  landmarks,  398 
Thoracic  duct,  142,  515,  516 
Thoracic  wall,  502 

surface  landmarks  of,  502 
Thumb,  dislocation  of,  93 
reduction  of,  95 

movements  of,  84 
Thymectomy,  166 
Thymus  gland,  166 
Thyreo- glossal  duct,  169 

cysts,  169,  170 
Thyreoid  gland,  166 

adenoma  of,  169 

blood-supply  of,  167 

capsule  of,  167 


INDEX 


555 


Thyreoid  gland  (contd.) — 
development  of,  169 
fixation  of,  168 
isthmus  of,  163 
lobes  of,  167 

pyramidal,  167,  169 
sheath  of,  167 
tumours  of,  168 
Thyreoidectomy,  167 
Thyreotomy,  162 
Tibia,  468 

fractures  of,  477 
ossification  of,  452,  481 
surgical  approach  to,  476 
tuberosity,  avulsion  of,  468 
Tic  douloureux,  233 
Tongue,  185 

development  of,  193 
foramen  caecum  of,  185 
frenulum  of,  186 
incisions  into,  187 
lymph  vessels  of,  186 
malignant  disease  of,  153,  186 
removal     of     lymph     glands, 

187 

removal  of,  187 
Tonsil,  lingual,  185 
palatine,  188 
blood-supply  of,  189 
development  of,  188 
enlargement  of,  188 
enucleation  of,  189 
lymph  vessels  of,  189 
malignant  disease  of,  189 
pharyngeal,  190 
Torti-collis,  116 
Trachea,  163 

pressure  on,  168 
Tracheotomy,  high,  164 
low,  165 
tube,  162 

Tract,  ilio-tibial,  401 
Transpyloric  plane,  240 
Traube's  space,  292 
Triangle,  deep,  of  neck,  138 
infra-clavicular,  superficial,  i 
lumbar,  of  Petit,  269 
posterior,  of  neck,  125 
exposure  of,  126 
fascial  floor  of,  112 
muscular  floor  of,  130 
suboccipital,  138 
urogenital,  376 
Trigone,  femoral,  408 
Tubal  gestation,  392 
projection,  190 


Tube,  auditory,  190,  212 
uterine,  391 

examination  of,  396 
fimbrias  of,  392 
Tubercle,    peroneal.      See    Process, 

trochlear 

Tuberculum  impar,  169 
Tubules,  seminiferous,  266 
Tunica  albuginea,  266 
vaginalis,  265 

hydrocele  of,  267 
Tympanic  antrum,  214 
aditus  to,  213,  215,  216 
pus  in,  215 

spread  of,  215 
surgical  approach  to,  215 
Tympanum,  212 
inflation  of,  190 

Ulna,  fractures  of,  68 

head  of,  66 

ossification  of,  58,  77 

proximal  extremity  of,  51 
ossification  of,  58 

styloid  process  of,  66 

surgical  approach  to,  73 
Ulnar  paresis,  127 
Upper  limb,  growth  of,  65 

measurements  of,  2 
Urachus,  381 
Ureter,  353,  354 

blood-supply  of,  354 

calculus  in,  362 

exposure  of,  275 

nerve-supply  of,  354 

pelvic  part,  362 

position  of,  346,  349 

referred  pain,  354 

surgical  approach  to,  363 

transplantation  of,  344 
Urethra,  female,  397 

blood-supply  of,  397 
Urethra,  male,  383 

cavernous  part  of,  384 

membranous  part  of,  383 

prostatic  part  of,  383 
openings  into,  383 

rupture  of,  378 

stricture  of,  384 
Urogenital  diaphragm,  378 
Uterus,  390 

cervix,  390 

development  of,  394 

ligaments  of,  387 
position  of,  390 
Utricle,  prostatic,  383 


556 


INDEX 


Uvula  vesicaa,  365 

Vagina,  388 

examination  of,  396 
Vallecula,  156 
Valves,  anal,  370 
colic  (ileo-caecal),  328 
rectal,  368 
Varicocele,  264 

surgical  approach,  262 
Vas  deferens.     See  Ductus  deferens 
Vater,  ampulla  of,  315 

surgical  approach  to,  316 
Vein  or  Veins — 

abdominal,  superficial,  243 

varicosity  of,  243 
anal,  371 
angular,  220 
axillary,  34 
azygos,  515 
basilic,  50 

median,  50 
cava  inferior,  352 

obstruction  of,  243 
cephalic,  6,  34,  50 
median,  50 
pressure  on,  37 
cerebellar,  224 
cerebral,  great,  223,  227 
cervical,  transverse,  131 
cystic,  312 

diploic,  injury  of,  227 
dorsal,  of  penis,  deep,  386 

superficial,  386 
emissary,  219 
condyloid,  220 
mastoid,  216 
parietal,  220 

facial,  anterior,  118,  147,  175 
communications  of,  175 
common,  117,  161 

injury  of,  135 
posterior,  118 
femoral,  408 

axial  anastomosis  of,  408 
haemorrhoidal,  370 
jugular,  anterior,  110,  166 
external,  108 

resection  of,  134 
internal,  116,  117,  224 
resection  of,  117 
septic  thrombosis  of,  213 
lingual,  119 
median,  50 
ophthalmic,  208 
pampiniform,  257 


Vein  or  Veins  (contd.) — 
para-umbilical,  243 
portal,  310 

anastomoses  of,  311 
obstruction  of,  243 
pterygoid  plexus,  181,  221 
pudendal  plexus,  365 
pyloric,  294 
renal,  352 
saphenous,  great,  398,  447 

varicosity  of,  448 
small,  447 

varicosity  of,  448 
scapular,  transverse,  131 
splenic,  321 
of  stomach,  298 
subscapular,  34 
superficial,  of  arm,  50 

of  forearm,  50 
thoraco-epigastric,  243 
thyreoid,  168 
inferior,  166 
middle,  119 
superior,  119 
vertebral,  141 
Ventricular  folds,  157 
Vertebrae,  ossification  of,  516 
Vertebral  column,  516 
caries  of,  520 
curvatures  of,  523 
angular,  520 
backward,  524 
forward,  524 
lateral,  523 
development  of,  533 
examination  of,  522 
fracture  dislocation  of,  529 

line  of  anaesthesia  in,  4 
injuries  of,  528 
luxation  of  articular  process,  528 

bilateral,  529 
movements  of,  523 
tuberculous  disease  of,  518 
muscular  rigidity  in,  520 
paraplegia  in,  522 
Verumontanum.    See  Crest,  urethral 
Vestibular  glands,  397 
Visceral  arches,  148 
clefts,  149 

remains  of,  150 
pouches,  149 
Viscero-motor  reflex,  298 
Viscero-sensory  reflex,  328 
Vitreous  body,  209 
Vocal  cords,  false.     See  Ventricular 
folds 


INDEX 


557 


Vocal  cords,  true.     See  Vocal  folds 

folds,  157 

Volkmann's  ischaemic   contracture, 
50 


Wharton,  duct  of. 

maxillary 

Wolffian  duct,  267 


See  Duct,  sub- 


Wrist,  region  of  65 

bony  landmarks  of,  65 
tuberculous  disease  in,  79 


Zone  of  ciliary  injection,  208 
Zygomatic  arch,  170 
bone,  fracture  of,  199 


THE  END 


q$$Zl   Bee 
B41      A 
1916      a 

sly,  L, 
manual  of  s 
natomy 

83933 

urgioal 



